Rick, Check out the magnetic building board on [link]http://www.airfieldmodels.com[/link]. His is a little elaborate, but it gives you some ideas. I designed some hold downs that I think are a little faster to use. Judging from the machinery in your shop, you could easily make a board and all the other stuff required in an afternoon.
On the servo mounting-I mount mine sideways in the wing all the time. I make up hardwood mounting blocks that are epoxied to a plywood plate that gets screwed between the ribs. This system is pretty common and I use it on most of my planes. I make up enough blocks at once for several planes since I'm jigged up for the cutting and drilling.