360 or 440?

If you do the 440;

A swap kit from Schumaucer (sp) http://www.engine-swaps.com/ is the easiest way to put the 440 in the swinger. Directions are easy to follow and do. I did a 318 - 400 swap in my Dodge Magnum, a '79 model car. It was easy.
Then you'll need a driveshaft to suite. Not a big deal, even more so if theres a shop in town.
The 8-1/4 rear will hold some decent power. As the ring gear size increases, the more power can be handled safely. Food for though when the power plan comes in.
The last thing would be T-bars. which you may want to upgrade so theres less bounce.
A consideration to think about is exhaust manifold fitment and where the exhaust dumps could be an issue or headers in which case, the coin on tti's may very well be justified.

360
The drivers motor mount only needs ethier it's proper mount or if you use the 318 mounts, washers to space out the gap due to the wider mount.
Otherwise, if the 360 cames with tranny/904 trans, same as the 318, it's a bolt in and go thing, no problem. A 727 tranny needs a shorter driveshaft.

Those are the basic pros and cons. Other than that listed, you'll save $500 by making use of what you have. (360) The 360 is better on gas.

Now, it's up to you on what engine you want under the hood when you pop it open.
Just one hint here, don't settle.