I have a 746 pro, a ts2000, a pegasus, and an Orion, ( and a ft 847 and 6 or 7 more)and I use the Orion most and the Peg second, the 746 pro is my station for visiting hams. it has a at 500 and a 2-kl. the orion is a better contester, but the 746 pro ain't bad. ( I also had a 756 and it was pretty good too.
go with the orion, or the orion II or keep the 756 pro and put $3000 or so into a tower and a nice 3 or 4 element steppir..
http://hometown.aol.com/catfishtwo/N6AJR.html pic of the shack