OK, now that I knew how much boost to run, I needed to know what parts to buy. I cheated here… I looked at other turbo kits to see what they have and then found out why each part is needed then formed my own parts list. Here are the parts needed for a basic 5 pound kit.

Part Part Number Where to get it
Turbo (stock WRX turbo) n/a Portland OR
-4 Oil Feed n/a ISR
-10 Oil Return Line Earls 200100 Frey Racing
Oil Pan Weld Fitting For The Oil Return Earls 967112 Frey Racing
Oil Return fitting into the Tap 800112 Frey Racing
2" up pipe n/a Unique Race Fab
2.5" Down Pipe n/a Unique Race Fab
Wastegate Deltagate External Wastegate Bought used from someone who upgraded to the TIAL wastegate
Weapon R intake SPOISBL SPO Motorsports
MAF Filter Mount n/a Kartboy Kustoms
2.25" 18 Gauge Stainless Steel Exhaust Tubing for the intake n/a Unique Race Fab
(2) 2.25" Silicone Hump Hose n/a Belair Composites
2.25" to 2.75" Silicon Transition Hose n/a Belair Composites
Intercooler SAAB 900 Ebay
Bosch Blow Off Valve n/a Turbonetincs
Autometer Phantom Boost Gauge  5703
Valve cover breather catch can n/a Made it
Autometer Mounting Cup 2204
Rx7 Fuel Pump  N/A Bought Used
Vortech RRFPR 6Z110-113FMU Bought Used
Autometer Air/Fuel Mixture Indicator 5775

Here are some parts I need or would like to upgrade to shortly.

Part Part Number Why Where to Get it
2.5" Borla Muffler n/a Better exhaust flow Devek
2.5" turbo back exhaust n/a Better flow Unique Race Fab
Autometer Phantom EGT Gauge and Probe 5765, 5244 Monitor exhaust temperatures

Recommended basic turbo kit parts if you are making your own kit. 

Part Price Why Where to Get it
WRX Turbo Usually about $300 for a used one.  Plentiful and can usually be had for about $300 From someone who upgraded or a wrecked WRX
RRFPR  $250 With this much more air, I need to increase the fuel Not sure yet or Devek
Up Pipe $200 Place to mount the Turbo Unique Race Fab
Down Pipe $225 Exhaust shops don't like making these.  Unique Race Fab
Oil Feed $35 Turbo needs oil Contact Paulnose on the I-Club
Oil Return $50 Need to get rid of the Oil Local race shop or Frey Racing
Intake Plumbing $100 To get the air from the turbo to the engine.  Unique Race Fab
Intake Plumbing Silicon connectors $30 To Hook up the connectors Belair Composites
Custom intake from airbox or CAI ??? Get clean filtered air to the turbo Make your own.
Zener Diode for map based cars or check valve.  ??? If a MAP sees boost on a MAP based car, it gets confused.  Radio Shack or an aquarium store. 
Air Fuel Meter $50 Need to know the mix when tuning the car Autometer Dealer.
External Wastegate $220 Keep the boost at 5 psi.  Turbonetics
SAAB 900 Intercooler $75 Keep the intake charge cool.  Ebay
TOTAL $1535