AFR (Air Flow Research) for the heads, a weiand intake manifold, and a 4 barrel carb of your choice, but don't go beyond 650 CFM. There are a ton of exhaust manifolds out there, just make sure it flows freely and get the ceramic coated ones. I'd put an exhaust system on there that flows freely. Be sure to include an "X" pipe on it. If you want a loud rattly sounding muffler, then go with the flowmaster 40 series, but if you want to be able to listen to that new stereo you are going to put in, then go with something a little more tame such as the Ravins that I have on mine or magnaflows. You might even consider the Borlas. They still have a rumble, but not that irritating rattle as the flows have. Go to the FAQ section in the classic section on here, and listen to the sound bites I have posted there. I know that most of this doesn't apply to your 2000 engine, but if you are going to replace the heads, then I would go with a carbureted system. I'm just thinking out loud here, so if this doesn't apply to you, then just ignore me.