Like 96blk54 said, best power bang for the buck seems to be a PI intake. There is a little extra work that needs to be done to fit one to PI heads but is doable in your driveway. Get a good used factory OEM or Ford Racing intake, avoid aftermarket (Dorman, etc.) intakes as they don't flow as well. However, if chasing cones is the goal, a stiff chassis and a great suspension with moderate power should give you better results than great power and a moderate suspension. Somebody please correct me here if I'm wrong. Also, don't forget the brakes!
Me, I haunt the local Craigslists for parts. I got a set of BBK shorty headers and an off road X pipe for $150. Cats are required where I live so I'm going to go with aftermarket cats on the pipes I already have. I got lowering springs, larger throttle bodies and plenums, front strut tower and rear shock tower braces, and other goodies cheap by being patient and keeping my eyes open. I tried to look up the class rules to see what you can do and not do but no luck, sorry. I would pass on used struts and shocks, unless you know their entire history and are 100% sure they are low mileage unabused pieces.
) and with OEM 8×17in rims. I'm looking into coilovers and a staggered setup with 9s in the front and 10.5 in the rear. Advice or others setups would be appreciated! 
