The 9242 is a true "two tuner" receiver, i.e. it is two separate receivers in one box. This is why it needs two cables in. You can set it up so that you can watch different programs on two different TVs. It does ship with two remotes - one IR only and one UHF - the UHF one can be used to control the second tuner from anywhere in a house.
As Nimiq pointed out, the only issue is that "tuner 2" does not send an "HD" feed, so the second TV would only get SD, not HD. If you could get either a component cable or HDMI cable from the 9242 to the TV in the basement, you could potentially get HD on that TV, but you'd have to watch the same channel as upstairs, i.e. you'd be getting a second HD feed off of tuner 1.
If you want a separate HD receiver for the basement TV and don't need a PVR, you can get used 6100s for a few hundred bucks or less. In fact, I think there's one for sale in the "buy sell" forum right now.
It looks like there's some deal at Best Buy right now that expires in a few hours to get a 9242 for $449. Since this is a purchase from a third party retailer, it would not typically include installation, which is a wholly a BEV service and, therefore, something you'd have to arrange with them. The 9242 replaces the 9200, which has virtually all of the same features, except the 9200 won't decipher "MPEG4" signals which BEV intends to start broadcasting in 2009. If you're OK with a receiver that may have limited or no HD capability two or three years down the road, you should be able to pick up a 9200 for $400 or less in the next few weeks (I just got one for $400).