I use the hauppauge HD PVR which is a USB based capture device. It works OOTB with Linuxmce and captures in 1080i HD which is good. I haven't been able to get it working with myth tv yet, but thats more down to my settings than anything else. It streams live tv to all my media directors which is what it needs to do for now.
Connection wise you have svhs, component, and composite, plus stereo audio connectors. It comes with a remote control too, but mine is still in the box, as Linuxmce handles all that.
Hope this is of some help.