I would buy current production GG switches. They are well made and the tracks are properly aligned. Some of the older production (10 or more years old) has issues with the way the various track pieces line up, which is poorly at best. They will work, but require a lot of tweaking. Not worth the hassle, IMHO. If you go manual, Caboose ground throws are great! If you go powered, DZ makes a nice, low profile switch machine. However, some people have reported issues with having them throw properly consistantly. NJs, while excellent and reliable, are also big and bulky. I'd look at an under-table mounting with a Rix-Rac.
Chris
LVHR