If you want to watch different HD programs on both TVs at the same time, then yes you need the second HD receiver. That could be as simple as a ViP211. However, consider feeding the 622's TV1 to both TVs, one using the HDMI connection and the other the component (plus L/R audio) connection. Then use one or the other of the composite TV2 (R/W/Y RCA jacks) or the "Agile Output" (coax) connection also to both TVs into either line-level or RF inputs as applicable. That way you can have HD and SD at both locations. If both want to watch the same HD channel at the same time, no problem. If the 2 locations want to watch different channels, then you get to fight over which one gets the HD capability while the other has to settle for SD. But that way you can at least have some HD capability in both locations at no additional cost. When watching the same HD channel in both locations, set the 622 in the Single mode and either remote can control it.
Welcome, BTW...!