Well i am planing for 1HZ just because i want to do some time really tourquey and different .. and yes u are correct that the engine bay might be a issue .. but thats all the fun to negotiate all these issue .. if its simple then no FUN 
But once its done it would be able to climb a Wall (H)
Also as far a SD33 is concerned i presume one can install a after market turbo on it with ease .. but still i will ask an expert on this matter and would let u know ..