Can someone buy an HDMI TV set top box?

[Enanas]

Hello . I have an HD TV on one set through a Scientific Atlanta Explorer 8300 HD cable box provided by Comcast. I have another HD capable TV in a different room that is on Scientific Atlanta 3100 digital box that is not HD. I can rent a 8300 box from Comcast
for $9.95 a month for the rest of my life, which seems an exhorbitant rip-off. Is there any way I can purchase a
compatible HD box that would work through the same cable feed as my other TV set?

 

[dEAne]

The HD box is configure to work with comcast other "compatible" is available but most are not legal.
From what I know.