hotchkis bushings vs. psc

[68firebird]

Before I found this forum, I was gonna get the performance suspension components g-maching handling kit. Now, thanks to this forum, I've been steered towards the hotchkis tvs kit. My question is what bushings are the better of the two, the polygraphite or the polyurethane/rubber bushings that hitchkis uses? I've read a few times on here that the poly ones squeak. I just wanna make the right decision here. I'm just going for an aggressive street setup. In case you need to know, I've got a 68 bird with a small block chevy and a completely stock suspension at the moment.