ok so, I had a NA auto harness and E.C.U....but can I buy a NA 5 speed harness and E.C.U, and plug it up. this is the only solution I can think of to my wiring problem...so wanted to run this by people who know the wiring.

 

To do such a thing you might need the harness (as stated - Check plugs for 5 speed to see if different) but also the key. Since the new lexus' all have transponders, I wouldn't know how'd you wire it up to your car.
I read your supraforums post, so best bet for your plans is go standalone, You might even spend less if you look around.
I've reasearched a ton since I plan on doing a 5 spd on my 98 GS300, I'm in the process and already have the majority of parts. If I figure any wiring issues out I'll keep you updated if you want.