Hey man I just joined today too, so I'm a fellow newbie.
I have had a 1998.5 Contour Svt for about 4 years now and as far as engine and transmission go I have had no problems at all. The car has been very reliable aside from an alternator that I had to replace a couple of years ago, I also had to replace both front wheel bearings but nothing very major. I don't know as much about the pre 1998 models but I believe most of the difference was cosmetic. Looking under the hood of my car the engine compartment is pretty tight so swapping the engine might be a pain but if you know what your are doing it probably would be no worse than any other car. Check the forums for tech advice, there's tons of stuff that I've found and I've only been looking for a few hours.