Has anyone heard of an AR based shooting platform other than the TPS Pro 5 capable of shooting Sub-MOA at 800 yards? If so what is it and were can I get one?[:\]

Actually, these should be pretty common.  Both service rifles and AR-based match rifles used in Highpower rifle competition are expected to group under 1 MOA out to 600 with iron sights.  A few intrepid souls use the same set-up out to 1000.  The biggest factor in making long range hits is the wind.

Post this over on the competition forum for lots of info or checkout their FAQ section.

HTH.....SRM