For the DC Market, a highly recommend going with a 2nd Dish 500 at 61.5 if possible. My signal levels were much lower (20 points) when I swung my 61.5 Dish 500 over to test 129...and I can't imagine how poor the signal levels would be with a Dish 1000. My signal levels are generally between 102-115 and I don't think I've ever experienced rain fade at 61.5 (EchoStar-3 or EchoStar-12).
I have a 622, 942, and 811 (5 tuners) and daisy-chained a 2nd DP-34 switch. I highly recommend keeping your OTA antenna in place if possible. HD LIL may be nice for some people not having an OTA antenna, but I quickly noticed the 720p channels are a bit softer (ABC, FOX)...,but not bad, and the 1080i channels are both soft and choppy (CBS, NBC)...watching the NCAA tournament on CBS (WUSA-DT 6360) was like being on LSD. The encoders still need work! Of course, I also have two OTA antennas (DC and Richmond) and I pre-wired the house for VOOM's Whole Home Networking solution (wishful thinking) and have 4-6 coax ran to each location.