2nd Gen MR2's had a 90 or 100 amp Denso option (looking for ones with the electric power steering assist). I don't know off the top of my head what it would take to fit it mechanically or electrically though. Most of my experience with Toyota's has been that similar years are pretty easily interchangeable.
I went with this alternator. Direct plug in. No splicing, no adapters, nothing special about the install. They use Denso parts. They've raised the prices quite a bit since I purchased mine though. It's worth the price, even though it's pretty steep.
Just stick with the cs-144, its fairly cheap and puts out 150amps if needed. only modification is 4 washers and a cheap adaptor. Takes 30 min or less to install, I even used the stock belt.
Personally id go with one of these three alternators! He is a member on here to under a different user name. His wiring kit "big 3" is pretty sweet too and very reasonably priced! If youre getting a higher amp alt you should really consider his kit with yhe alt and big 3 wiring upgrade.