Good luck. But from personal experience, you would be ahead with a tripod and the Dish 500 antenna that picks up 110 & 119.
Dish 500 receiver? Do you mean a 501, 508 or 510 DVR?
I used a tripod setup with my old 301, many years ago. I now have HD, and am more inclined to wait for Archos to get their new devices working with Dish ViP series HD DVRs. They'd get my money in a heartbeat.
Of course, sometime this summer, I will move a cheap Blu-ray player to my RV. That, and the stack of DVDs and the DTVPal HD DVR - and I'm well set.