I like the polygraphite bushings, that's what I have everywhere I can replace bushings. Its definitely stiffer, you get less play in the suspension and it also makes your inputs a lot more accurate. But it can be a little harsher, you feel more of the little bumps. Poly bushings do have a tendency to squeak though, so everywhere you can add grease fittings do it, that way when it starts to squeak you can add more grease. The A-arms I got from CAP came with them, then I supplemented the rest with Energy Suspension components, which Summit sells.
Some guys don't like them, mostly because of the squeaking, and rubber is more compliant, so rubber bushings are easier to install too. But if you address the squeaking with more grease fittings (FFI sells greaseable LCA pins) its not really an issue. And I value the accuracy in my suspension more than a few squeaks.
There was just a thread on here somewhere on the correct finish for suspension stuff, I'd check there. Most of the stuff, like the LCA's and strut rods, were just bare metal with a coating of oil/grease.