"Pet" classes other than Summoner?

[Extra Anchovies]

3.5 or Pathfinder, actually.

What I'm looking for is something that grants a scaling-power customizable beatstick companion, a la the Eidolon, and has the spells to buff it up, but doesn't have the Summon Monster ability. I don't like Summon Monster, because keeping track of all those complex statblocks is annoying. Summon Nature's Ally would be fine, since those are just more beatsticks, so I've considered the Naturalist and Wild Caller archetypes, but preferably something that doesn't do any minionmancy beyond the single companion would be optimal.

Does anything of the sort exist outside of homebrew?

Also, comparing Naturalist and Wild Caller: which is better? The animal aspects from Naturalist are a good way to buff the eidolon, but so is the bonus evolution points from Wild Caller. Naturalist (oddly enough) can still summon outsiders via Gate, but the Summon Elder Worm ability of Wild Caller would be hecka fun too.

[Ninjaxenomorph]

Are you sure there isn't an archetype that removes Summon Monster? Or you could just not use it. Other than the summoner, I think the Hunter is the best AC class Pathfinder has.

[Tryxx]

Have you considered a Psion (Shaper) and Astral Construct? The book keeping isn't bad and there's plenty of utility - especially with the Boost Construct feat.

[Roadie]

Nightmare constructor (http://www.d20pfsrd.com/psionics-unleashed/classes/dread/archetypes/dreamscarred-press/nightmare-constructor) dread (http://www.d20pfsrd.com/psionics-unleashed/classes/dread) and ectopic artisan (http://www.d20pfsrd.com/psionics-unleashed/classes/aegis/archetypes/dreamscarred-press/ectopic-artisan) aegis (http://www.d20pfsrd.com/psionics-unleashed/classes/aegis) both work if you can use Dreamscarred psionics material.

[Forrestfire]

Have you considered a Psion (Shaper) and Astral Construct? The book keeping isn't bad and there's plenty of utility - especially with the Boost Construct feat.

There's also an ACF (http://archive.wizards.com/default.asp?x=dnd/psm/20070411a) that lets you summon a personalized astral construct as a swift action, and a PrC (http://archive.wizards.com/default.asp?x=dnd/psm/20040625b) that buffs the power a ton. It's a very fun archetype to play.

[(Un)Inspired]

Although pathfinder die powered them dramatically, the Druid is still a pretty good class with a strong pet.

Allosaurus for the win!

[AvatarVecna]

Unfortunately, while there's a few ways to get constant beatstick companions, there's no way to really customize them beyond the normal level up process. The interesting thing I've found is the 3.5 Beastmaster (I'd link to it, but...well, you know): in 3.5, you could be a Druid dipping into Beastmaster. Although it doesn't advance spellcasting, it advances your animal companion: the first level ability gives you a companion equal to your class level +3; if you have druid levels, they stack. Furthermore, the example the ability lists of a Druid/Beastmaster shows a character with 5 levels of Druid and 2 of Beastmaster, and it says that it has an effective Druid level of 10 for the purposes of determining their animal companions abilities, as well as determining what powerful companions you can use. This proves that it's RAW legal to have a higher effective druid level for animal companion purposes than your character level.

The 2nd level of Beastmaster is arguably better than the 19th level of Druid, but I doubt you really want to be 2 levels behind in spellcasting for the middle and final third of your career. My advice: take Druid to 6th level (for Wild Shape and Natural Spell), then dip into Beastmaster for 1 level. Take several more levels of Druid until you'd be satisfied being another level behind (my suggestion: stop at Druid 18), then take the second level of Beastmaster: 2 levels of Beastmaster gives +2 BAB, +3 Fort, +3 Ref, the additional effective Druid levels for Animal Companion purposes, and the Alertness feat. Of course, some people will prefer a few extra spells, and will go Druid 19/Beastmaster 1, and that's cool, too.

Honestly, I wanna recommend another PrC to throw in there: maybe Warshaper, of Nature's Warrior, or some Buff-Master PrC. Unfortunately, the speed at which I can search for 3.5 material is so slow at this point in time that it's surpassing my ability to care about helping others with their hypothetical builds. Really sorry about that: maybe someone else with a little more patience than me could expand on this idea, or even present a better one.

My only other note is that, a while back, I came across a halfling commoner that tamed a T-rex by level 6 or something. It abused the Handle Animal skill; seeing as you would have to take Skill Focus (Handle Animal) to get into this PrC, I recommend abusing the skill yourself if you go this route.

[deuxhero]

Keep in mind that you can't use your summon monster SLA while your Eidolon is out (which it always should be). This restricts it to being a backup option if your Eidolon is taken out or if you are attacked while sleeping. Spirit Summoner can be used to replace the SLA with hexes.

Aasimar Lunar Oracle is a very potent option. Spending your favored class bonus to boost Primal Companion and taking Evolved Companion, Spirit's Gift and Celestial Companion makes it powerhouse, and you're still a full caster behind the giant mutant celestial cat (and there's room for several other Oracle tricks in such a build too, like making dexterity useless so you can dump it freely and or taking the Spirit Guide archetype for spells).

[Sayt]

The hunter is a decent pet class, It gets a full progression animal companion, and free teamwork feats which it automatically shares with their animal companions.

[Ssalarn]

The hunter is a decent pet class, It gets a full progression animal companion, and free teamwork feats which it automatically shares with their animal companions.

Hunter also has an archetype that lets you give your pet evolutions.

[ninjamaster1991]

The Eidolon Anchoring Harness lets you use Summon Monster uses to keep your Eidolon around longer - either a single use for once-off effects like Dismissal or 1/round for persistent things like an AMF (which is arguable), unconsciousness (of either the Eidolon or the Summoner), or the Summon Eidolon duration expiring.