well in QLD an SR20DET is illegal to install and the only rotary allowed is a 12A.

I think the SR20 would be easier to install in the long run, as you don't have to worry about oil cooler and lines etc. But with all turbo applications there is alot of modifications to make like upgrading fuel system and wiring in an ECU etc. But hey if you handy with your hands you can do it all yourself you just have to find an engineer who will approve the conversion, but having said that it's still illegal and in a crash if thats found out you lose your CTP and what other insurance you have due to an unroadworthy car.

Sorry to be the bad bringer of news but I've already gone through checking all this out. (Talk to tappet or 2quik4u they both have SR20's installed they maybe able to help you out)

Cheers
Damo