360 or 440

I'd do the 360 for the following reasons;

Easy bolt in.
Slightly cheaper than a big block.
Slightly better handleing than a big block.
Lighter in weight from the get go or even when aluminum is swap in.

The big block has it's advantages as well starting with a much larger dispalcement. But all in all, it would be a tad more expensive and a little harder to do.