have you ever had nitrous on a motor? let say you had a cheater kit on a carb'd 5.0, you set it up with the 75 HP jets, drive it for a while, like it, but the thought kept nagging in the back of your mind... this kit has upto a 250 HP jets... are you gonna leave the 75 HP jets in it???? chances are no.
with that said, no, low compression is not REQUIRED, for that matter forged pistons are not REQUIRED. IF you are not going to boost the motor more than... maybe 5 lbs. of boost... if that is all the boost you want, why bother? its alot of work for 5 lbs. of boost.
so to qualify my previous statements... if you are to make the most of the work you are wanting to attempt. use lower compression forged pistons. even a set of used TC pistons would be better than stock cast pistons.
there are alot of opinions on the whole turbo thing... the previous are mine.
have fun...