Len, welcome to the forum. I can't comment on the deal because I'm not sure how much they go new but it sounds like a pretty decent price. I'm assuming you're going to keep it in the water considering the "bottom paint"?
The 5.0 should do fine on that boat. You'll be able to wakeboard, ski and tube with no problems. It won't be the fastest thing out of the water but it will do the job.
I've got a 236LS with the 5.7 and it's a great setup. Your 220EX should be a tad lighter so I think you'll be happy with it.