If you want more of a switchers I'd use a DVDO scaler. The VP20, VP30 and VP50 all perform conversion to HDMI. They start at around 1600 but also perform the added value of actually processing the video and scaling it to a higher output resolution. (Crappy analog video will look less crappy on your HDTV).
If you want a receiver that just converts the video the Denon 2807 or Yamaha 2600 both perform upconversion as do thier higher end models.