I think I can be of some help here.
I just bought a used custom turbo kit. Here are some of the things I bought.
J&S Ultra safeguard V2- $535 + $165 for dual monitor
Walbro 255 HP in-tank fuel pump- $150
Greddy turbo timer- $100
Greddy Profec B electronic boost controller- $315
Tial 35 mm WG with 5.8 psi spring- $250
HPC extreme heat coating- $650
Jacobs ICE-PAK ignition- $375
7 series NGK spark plugs- $10
Ultra plug wires- $140
Also, gauges will cost plenty more that about $100 or so. Ones that I would definately get are...
J&S dual monitor- $165
- not only does this allow you to check your A/F, it also allows you to tune you car based on the level of det. occuring. You can continuously tune your car until you get no det. at all using this monitor, which is ideal for a turbo car
EGT gauge- $60-$250 depending on which you get
- a more accurate way of monitoring and tuning you fuel management because it tells you if you are running lean or rich.
Fuel pressure gauge- $50-$200(mech/elect)
- this one is self-explanitory
Boost gauge- $50-$250(autometer/Apex EL series)
- again, self-explanitory
Plus figure in about $50 for 2 universal dual pod holder. You can cut one into 2 single pod holders, and then line 3 up on the driver's side and one on the passengers.
I would also strongly suggest if you go with a custom kit(a better bet IMO over a shelf kit but costly and somewhat of a PITA to fit together), order a set of dual FAL electric radiator fans(for a 3rd gen integra from Summit for $315), as the stock fans are too deep, not too mention, don't cool as well. Add on another $10 for water wetter too to help keep the car cool, along with a Spoon Thermostat and Mugen radiator cap too. All small but worthwhile extras to insure safe/optimal running conditions. Also $25-$30 for 6 quarts of synthetic oil, as you will need to get it changed via install.
Almost forgot, for those that opt to "pass" on the J&S safeguard, please spend the $75 to get the missing link check valve.
So as you can see, turbo IS an expensive process. Also, if you really want to extract the most from your kit, a 3" cat-back exhaust is a good investment. However, no one makes one for the Lude.
You can do one of 2 things... buy a Tanabe RM for a RX-7 and take it to a shop to have it fit to your car OR custom make your own one. I have done some estimates on the cost of building a custom one. Either way, you will also(or should also) plan on either getting a test pipe or a 3" cat to eliminate the bottleneck effect on exhaust flow.
Figures are calculated from
www.burnsstainless.com for 3" 304 SS piping...
(1) "U" bend= $68
(1) "15 degree" bend= $45
(1) "45 degree" bend= $47
7.5 ft. of straight pipe= $115
Total w/out shipping = $275
Add onto that about $150-$250 for a good SS 3" muffler(like a N1 universal or a Borla XR-1), plus another $300 or so for a 3" cat, and you are looking at $765 plus installation ~$100 or so, plus $50 for flange plates and hangers, and you are looking at about $950 all together for a job well done.
So Thermal RD if you are out there listening- MAKE A 3" SS EXHAUST FOR OUR LUDES!!!
Good luck and happy boosting! I know I can't wait!