Engine Swap Questions

I have searched Google until my fingers went numb, but still can't find
a definite answer to these questions:

What other engine(s) (besides the B20Ax and B21A1) will fit in a 3G
(88-91) Prelude with minimal mods?

If I go with something like an F22 series, will I need a new
transmission and ECU?

Do all B20x series use the same transmission?

Is there a site other than www.tigerjapanese.com that has great prices
on used engines?


Thanks in advance!