youd be better off buying a 3sgte - but if you must go to all this hassle of making one yourself - just remeber you wont be able to run alot of boost - the pistons will shit themselves pretty quick at that compression ratio ..
you REALLY should see if you can get a gen3 3sgte motor from a turbo MR2 - and use that as your basis ..
That motor Stock - will handle 15 psi plus withiut a hint of struggle or fuss , though your gearbox wont handle this power for very long without upgrading it - and the clutch as well
youd want the 2jzgTe ones too - if you want larger injectors .. though , once again - a gen3 3sgte has these already - 540cc denso units
The ct20B is a better turbo to use for most applications - which also comes with the gen3 3sgte motor ..
gen3 motor also has better head design , better inlet design , and alot of other goodies ..
ERL would be a recommended system for water injection - youll need this and a decent intercooler setup ( ironically once again ! the gen3 3sgte comes with an excellent water to air intercooler - if you get it from a gt4 ) unless you want to face detonation issues