Here is a checklist to go by. In my OPINION this is the mininual stuff you need to have a small successful custom turbo kit. If I mentioned brands for an item its important to get a brand name item. Skipping on that would really hurt your power, but bear in mind there are more good brands than what I mentioned that is just what I have encoutered. What you should spend on each part is in ( ) .
TURBO PARTS:::
Intercooler (200 - 400) - PWR, Greddy, Drag, Speaco, Tyan, HKS
Intercooler Piping (100 - 200)
Intercooler Piping Couplers (25 - 75)
Air Filter (50 - 75) K&N accept nothing else
Turbo (100 - 400) Garrett, Mits., Turbotechnics, Stock turbo from a car
Turbo Oil Lines (50 - 125)
Waste Gate (100 - 200) Tial they are the best
Turbo Manifold (200 - 400) avoid: ebay no names, and drag
Blow Off Valve (50 -200) I recommend a first gen dsm bov, or name brand
Fuel Injectors (50 - 80) DSM 450cc blue or black tops
Resistor Box (15 - 30) it must be from a 88-91 honda
Uberdata (175 - 250) this is for the programmer and parts the app. is free
Intank Fuel Pump (75 - 100) Walboro 255 intank pump or Holley 255 intank pump
Fuel Pressure Regulator (50 - 100) B&M, AEM, STR, or others
NECESSARY ENGINE PARTS:::
Water Pump 75
Timing Belt 50
OPTIONAL PARTS:::
Fuel Filter (15 - 40)
Adjustable Cam gears (100 - 200)
Piston Rings (50 - 100)
Head Gasket (40 - 85)
ARP Rod Bolts (85 - 125)
ARP Head Studs (85 - 150)
Clutch (250 - 400)
Oil Pressure Gauge (30 - 70)
EGT Gauge (75 - 150)
PSI Gauge (30 - 75)
Crank Bolt (15 - 30)
Traction Bar (300 - 400)
Poly Motor Mount Inserts (50 - 100)