RE Intercoolers...
If you want a factory item, grab one off either a 88-93 Toyota Supra (looks like the last one you posted) or a 88-92 Mitsubishi Galant VR4 (Japanese version, it looks like an aftermarket cooler). They are the ONLY two factory coolers worth anything (lancer evolution coolers are also good, but are EXTREMELY pricey).
ARE.com.au and PWR.com.au are the only other places i'd consider getting a cooler from as all the "
ebay" special coolers generally have massive pressure drops over the core and/or aren't rugged enough in the welds to survive serious offroad abuse. You will also need to fabricate mounts for the cooler and I SUGGEST you put rubber washers between the chassis and the actual mount to absorb at least some of the vibrations.
Silicon hose should be used on either end of the cooler and connected to hardpipes, try to use at least 4 sections of silicon on the entire system, generally around 6. Two for the intercooler, one for the throttlebody one for the compressor outlet. If you have to put an expander on the system (the throttlebody is bigger than the intercooler outlet), then put it as close to the throttlebody as possible as it creates turbulence in the pipes and can cause power loss.
If you use mild steel for the intercooler pipes, have it ceramic or gal dipped otherwise the inside of the pipework will rust and will go into your engine. Don't argue, i've killed a 4g63 (lancer evolution) engine like this. If they're stainless, use extra silicon as stainless can expand as much as 3 full inches with the heat depending on the pipe length and wall thickness. If you use aluminium, make sure the welds are properly done as it has a tendency to possibly leak.
The location you mount your cooler is upto you, you need somewhere that has good airflow. Usual places for Aussie cars is up top with a topmount (generally off a subaru WRX) using a GU patrol bonnet scoop cut through the bonnet and an 8 inch thermo fan under the intercooler to pull air through at low speeds and/or temperature switches against intake temp. This can add up to a lot of money though. Steer clear of water to air setups as in low speed 4x4ing they'll overheat pretty quickly (they're effectively a small radiator without coolant).
Anything else you need to know feel free to PM me.
