It was model HDS220R and I think it was a Hughes made unit under the Hitachi name. It was great for the time, but today I wouldn't pay more than $50 for it. I am sure you can have the most basic features, but you would be better off with at least one of the $299 deals for the HD intro receiver that many companies are offering or you can get great deals on ebay for a top unit for about the same or less. As with all ebay, research the seller and their terms carefully.
charper1, you are 100% correct. The Hitachi DIRECTV HD STB was made by Hughes and it's the old Hughes E86.
And Jason, you are also correct, the all time best DIRECTV HD STB ever made was the LG LSS-3200A, which is also labeled under the Sony HD-300 and Hughes HTL-HD.
The best DIRECTV HD STB currently availability is the new RCA DTC-210.