Nice find!
Limited funds = more do-it-yourself.
I'd start by pulling the trim, engine, the interior, the wiring, and the fuel system. Store and label everything very carefully. Keeping a photo journal helps a ton. Some of the smallest things seem to cost the most on these cars. Trim especially. You can probably spend the same amount on really nice wheel opening trim for the cost of a running 440 out of a new yorker, so be careful pulling some of that stuff off.
Then take stock of what you have left on the body. Look at the frame rails, the floor pans, the inner fender walls, the door jambs and decide if you can afford to send the car out to a body shop, or do the rust repair and body blocking yourself. I chose to send mine out, even though it did not have nearly as much rust showing as yours seems to have. It's not impossible to do this yourself, but I'm going to guess you will need a replacement fender, rocker panels, some quarter patches and I'll also bet your inner fender walls will need some lovin'. Don't skimp on the body. Seriously, the body is the rarest part of any of these cars, and if your going to put even any money into a project like this, make sure that it will last as a long as possible. A strong 440 will be worthless if the car is rusting away around it.
While the body and paint work is being done, you can start mulling over your power train, suspension and handling options. This is where you decide how much you can or want to do yourself. I made spreadsheets of every option I wanted and did some web research for the cost of each option package. Older 440 engines can be had pretty cheap on ebay or craigslist, but shipping will hurt, and then you will probably want to do a lot of work on it before dropping it in. And going from a 318 to a 440 means a lot of upgrades along the way: new suspension, bigger brakes, different transmission, sturdier rear end, different engine harness, different fuel system, different accessories... a lot changes with the power plant.
My 2cents.