Welcome to the site, and it looks like you've got a lot of work ahead of you. I'll offer you the same advice I offer everyone, and that is don't worry about the bodywork until last. It can suck up every dollar you have and once they're gone you have nothing but a painted body to show for it, which kills morale and enthusiasm quickly. Also, if you've already got rust coming through the primer, it's very likely whoever did the primer did a really crappy job of prepping the body, so you're going to be constantly fighting rust issues as they pop up. Better to get other stuff done and attack the body issues all at once.
The first thing I would do is start getting the car put back together. Get the gas tank in, interior in, etc. The sooner you can get the car from the pile of parts stage to the sitting in it stage the sooner your enthusiasm will increase.
Next, for the 440, you're also going to need a big block transmission and maybe a driveshaft. As for what you'll need for the engine, there's a LOT if all you have is the engine itself. You need engine management items (carb, distributor, and ignition system), accessories (alternator, power steering pump, water pump, etc.), brackets, belts, bolts, and spacers for all those, pulleys, sender units for temp and oil pressure, bypass hoze nozzles, throttle brackets, springs, and mounts, kickdown lever, and an exhaust system. You're also going to need a set of Schumacher engine swap mounts (look at the Engine Swaps link on the right side of this page).
To be honest, I tried the "buy an engine and then all the parts" method, and it's a pain in the *** and can get expensive. I found the better approach is to find an old car or motorhome with a complete drive train in it, buy it, and pull the drive train out. That way you have most all of the parts and pieces you need.
