Building an Ultimate Magus

[Palanan]

I could use advice on how to flesh out an Ultimate Magus using Pathfinder material. The progression I’m starting with is Sorc 1/Witch 3/UM 6. (I’m aware the witch doesn’t cast from a spellbook, but it’s close enough for my purposes.)

The character is a seducer witch with fiery tendencies on the sorcerer side, and what I need help with is selecting feats, traits, and items from Pathfinder material that would make the most of the concept. I’m open to all constructive suggestions using first-party Paizo sources. I don't have much experience using metamagic in caster builds, so I'd especially appreciate any suggestions using PF's metamagic options.

[Eldonauran]

I'm not familiar with an 'Ultimate Magus' in the Pathfinder 1st party sources. Is this the prestige class from 3.5e that you are using pathfinder classes to qualify for?

[Palanan]

Originally Posted by Eldonauran
Is this the prestige class from 3.5e that you are using pathfinder classes to qualify for?

Exactly so. This is the Ultimate Magus from p.77 of Complete Mage, which I’m tweaking to bring in line with Pathfinder standards.

That’s the only 3.5 element of the build; I’d like everything else to be from Pathfinder. Sorcerer (elemental) and witch (seducer) are fixed, but what I really need advice on is feats involving metamagic, and also items that might be especially useful for an Ultimate Magus in a Pathfinder environment.

[vasilidor]

Reach spell is good for avoiding getting close to enemies. each range increase also increases the spell level though. It makes a lot of touch spells better though.
Most of the other metamagic feats I would recommend are 3.5 feats that exist in Pathfinder with almost no change.

[Palanan]

Originally Posted by vasilidor
Reach spell is good for avoiding getting close to enemies….

Most of the other metamagic feats I would recommend are 3.5 feats that exist in Pathfinder with almost no change.

Reach spell sounds ideal for the character I have in mind, thanks.

What are the other metamagic feats you'd recommend? If they’re in both 3.5 and Pathfinder that’s fine for my purposes.

[vasilidor]

If you want a damage boost, Empower Spell.
Quicken Spell is costly but can be a life saver, especially at high levels. Get a rod for it if you can.
Spell Penetration and Greater Spell Penetration may well be needed if you have issues getting your spells to work on targets with spell resistance. Being an Elf can help with that to if you have not set your heart on another race.
Elemental Spell is nerfed, now having a +1 to spell level to change the damage type of the spell, but can be worth it if you need the damage boost or bypass an immunity.
Oh, a new Metamagic feat I had forgotten about is Bouncing Spell. First target makes their save on an all or nothing spell? pick a new target for +1 spell level.

[Jay R]

The basics are basics for a reason.

Quicken Spell. With an extra 4th level slot, you cast twice as many spells in a round. This has a huge effect on the action economy.
Empower Spell and/or Maximize Spell. Bigger effect.
Reach Spell. Stay away from the danger.