you will need:
PI Intake Manifold
PI Heater Return Tube (tube that runs under the intake manifold)
PI Water Pump Nipple (if your car is a 98, you already have this)
PI Intake Manifold Gaskets
1 Bottle of RTV Gasket Maker
PI Cams
PI Cam Bolt (NPI bolts are too thick to work)
Valve Cover Gaskets (im a firm believer in replacing any gaskets when you can)
Engine Assembly Lube
Torque Wrench (in-lbs)
Fuel Line Removal Kit ($2 at autozone)
Assorted Tools
if you go the more involved way for the Cam install (removing the timing cover), you will also need:
Timing Cover Gaskets (3 of them)
Timing Cover Seal
Pulley Remover (rent one at autozone)
and thats all i can think of. buy some cans of brake cleaner too so you can clean parts as you take them off and before you install them.