As always, that depends on how much you want to spend.
Do you have the money to spend on titanium valves and exotic heads or are you thinking cast iron and steel?
If it were me (and it is...but a 351 instead of a 302) I'd look at the following to get you started on the intake side of things:
Heads:
The GT-40P cylinder head (flows about 190 stock) and with larger valves (1.84I, 1.48E stock size) and some mild porting (mostly just unshrouding and enlarging below the seat to match the larger valves) will breath well enough to get you into the 400+ horsepower range and not be too expensive as compared to aluminum. Put some undercut swirl polished valves (PAW sells a nice valve for about $11.50 each) in size 1.94 intake and 1.6 exhaust and you're good to go.
If you want aluminum, then the Twisted Wedge heads make some power, but it is my understanding that the valve train should be upgraded (get the bare heads and buy the rest yourself). The AFR heads seem to wrok well on the 302 also. The Ford aluminum isn't quite as good.
Intake:
Again, it depends but this time if you are going to go fuel injected or not. If so, there are plenty or articles around on the net to get you started. If not, then I like the Perfromer RPM for street use. Good (or so Edelbrock says) to a 6500 RPM power range. If a higher revving engine is your goal, then the Torker intake is nice or maybe a Stealth.
Cam:
Well, again it depends on how much money you plan to spend and what RPM range you want to make power in (gearing comes into play). If going low $, then I'd go with a hydraulic cam and strongly look at variable duration lifters if you plan to run too much cam. If more high $, then I'd convert to a hyraulic roller. My self, I really like the Comp Cams 290 retrofit (hydraulic to hydraulic roller) cam, but this is probably a bit too much for a 302 on the street.
Summit is a good source as is PAW (what Summit doesn't list they can usually get, but PAW will already have it in their book).
Good luck.
[ February 22, 2002: Message edited by: Darrin ]