Primary shieldbashing, viable?

[Castilonium]

I have a rules/optimization question regarding shields, but first, let me set up the situation:

Our party is playing in a setting with strong firearms, so we're heavy on spellcasters and ranged attackers, and light on melee. I'm trying to become a sturdy character who's still threatening enough that monsters won't simply ignore. Summon Monster spells have been houseruled to a duration of concentration, so it's trickier to summon expendable meatshields. Primarily we use terrain and control spells to protect ourselves, but there are times we would benefit from a strong defensive melee character. Also, spiked chains aren't allowed.

I'm trying to figure out the best option for a weapon, and I'm thinking of using one shield in two hands for the 1.5x strength bonus and the extra damage on power attack. Since heavy shields are a one-handed weapon, I should be able to use it in two hands. With shield spikes, the bashing enchantment, and the improved shield bash feat, I'd hit for 2d6 damage, but still have a lot of AC from the shield.

Is this legal? And is this a better option for me than using a more standard weapon like a greatsword or a reach weapon?

[Flickerdart]

It's legal, but you're putting a huge amount of effort into having a marginal bonus to AC. Just get an amulet of natural armor instead, and at higher levels, buy an animated shield.

As for your summoners, tell them about Sonorous Hum.

[Castilonium]

Sorry I forgot to mention in my first post, but Animated shields cost +5 rather than +2 in our campaign. That might be too expensive of an option for me right now.

Sonorous Hum looks very useful. I'll ask my GM if it'll be acceptable, since it's from Savage Species.

[olentu]

Sonorous Hum looks very useful. I'll ask my GM if it'll be acceptable, since it's from Savage Species.

It was reprinted in the spell compendium.

[zlefin]

You can use improved buckler defense (complete warrior) to benefit from a buckler while still using a 2 handed weapon.
Is this PF or 3.5?

[Gorgondantess]

No, just focus on increasing your attacking power so that you can slaughter your enemies before they get a chance to hurt you. 2-H weapons give a MASSIVE offensive boost over sword and board.
The best defense is a good offense, and that is 100% true in D&D.
Now, if you want to be a "tank", you can be defensively offensive- that is, focus on locking your opponents down rather than absorbing damage. Improved trip+Stand still and a reach weapon works wonders for this.