What Ian said, the smallport onwards uses the same block & crank.
This is one of the threads from toymods, can't find the other:
http://www.toymods.org.au/forums/showthread.php?t=29777
Perhaps speak to them about the SC on a 20v then.
10 & 12psi is pretty standard, Glen from wolf metalcraft is getting over 14psi out of his and has been for quite some time.
And a bigport has a C/R of 9.4:1 and people have ran them on 10psi with a stock ecu happily, I believe one was going for 3 years.