i just recently put on the tl-s sway bar and i'm running on stock springs/shocks for tires i'm using SP5000s and the difference is amazing. The car sticks much better during turns and a bit less body roll. The whole kit only cost $100cdn which is about 70us. The size is the same as neuspeed's rear bar. As for changing the front, i don't know if you'll feel that much of a difference since its already pretty thick, and how often are you going to feel oversteer in a fwd. There is still body roll during long on/off ramps but that can be changed with a good spring/shock combo.

TL-Type S sway bar = best mod for the money!
*My two cents*