Oh goodness...that oughta open up a can of worms!

There's a slew of upper control arms to give you more caster/camber adjustments, sway bars, springs/4-links, aftermarket steering boxes/upgrades. It really comes down to what you want/have to spend.

As for the second half of that question- aside from saving some weight, you're going to be buying the same parts for an A-body that you would for the B-body. Looking at the thread on car weight bias, on average they all seem to be about 55/45 front to rear, so no real advantage there. Can you afford to build 2 cars? Might be worth doing an A-body for corner carving if you can. Money's tight? Take advantage of other's knowledge ahead of you. Pay particular attention to ones like AlexP's build in this section. Keep your eyes peeled for the deals and build away!