I use an old D2 (or DII, I forget which one - and what is the difference?) with an Aristo cold light. Mine is tall enough to make a 16x20 with 35mm and 4x5, and is no more than 4ft tall (not at home at the moment, so I can't measure). One thing I've always liked about the Omegas - you can align the negative stage at each corner for level to the lens and base board. I had a Beseler 45M once, got it used, it wasn't level and there was nothing I could do about it.
Like someone said, get all the extras and accessories you can, you never know what you will need.
There is a popular web site for lots of vintage parts, someone can chime in with that.