The stock 3s generally ends up around 350whp before you hit the start of diminishing returns on your money.

With 10,000 invested and most of the work done by yourself, you will most likely make close to 300whp and still be very reliable. This is MORE THAN ENOUGH to run low 12's in an mr2 and high 13's in the celica. At this point, the cost of going from 300whp to 400whp is EXPONENTIALLY HIGHER as many pieces of the drivetrain need to be replaced for strength reasons. Judging by the questions your asking, you seem fairly new to the 3sgte, this is not a "plug and play" solution, but it is one of the better options for toyota swaps.

Gotta Pay to Play

Also, Twin Turbo is a bad idea on any 4 cyl application. Most people in the forced induction business tend to lean towards the fact that a properly sized larger turbine is always better than two smaller turbines due to turbulence and mechanical friction of more moving parts in the 2 smallers.