Mark:
As far as the turntables go, just keep an eye out. The Atlas ones surface from time to time and will continue too. I'm betting that if you posted WANTED on here someone would have 1 or two. BEFORE you do, and again you've got time, you might keep an eye out for someone selling an old used Bowser or another higher quality turntable. Here's more great news for you, you don't need a motor, indexing etc. as both turntables are easily accessible. Yes if they had motors that would be fine, but you won't need motors. Manual is fine. You will find a good deal if you are patient.
Also, you could go crazy like I did and build one. I built a small one that catches everyone's attention. They ask me who made it. I'm kind of embarrassed to admit it's a cake pan with an upside down HO scale girder bridge. I use it for turning the old rotary snow plow. It's functional and looks realistic. No it's not in a league with Ross or MillRiver Studios, but it cost me $17 to make and not $1200 or more.
NEXT: INTERESTING FACT! Davis is the highest town at 3100 feet in all of West Virginia! Second, under Cheat Mountain there's a tunnel leading out to a connection with the C & O and B & O. It would be cool to put a turnout o the line with a track leading to a backdrop portal (painted or 3D) that gives the appearance the train is entering a tunnel...that would be your interchange/connection to the world. If somehow you can position a small mirror inside a tunnel portal facing out it provides a great illusion like track is traveling through tunnel. I've never tried it but I've seen photos.
