About $5k in Lotus parts, some of those sourced from other places.
ECU... depends. I had the EFI running the engine, but it does cost $3k or so. The good thing is most of the tuning is done and can be gotten from DRS in La Habra and then you can tweak/dyno. Or you can get a reflash done on the stock ECU cheaper, but then there is no way to change the tune easily for E-85, 100 octane, high elevations, etc.
LSD- You can get a Toyota supplied tranny or differential. Probably easier to swap the entire tranny and also install a lighter flywheel and better clutch.
ASP makes a LOT more sense. You can get the car under 1900 pounds and over 250hp and just about as much tire as you want (too much).
2006 Noble M400 (E-Mod?)
http://chasecam.com/ official supplier to SCCA Pro Racing. Sponsor for SCCA ProSolo. Supplier to MazdaSpeed, V8Supercars, etc.