I would not even be bothered to care about VP in a receiver until you can afford at least Reon, Realta, or Anchor Bay. IOW, $1k and up. And even then, its quite plausible that your display does just as good of a job, or that's its so close that its basically wasted money.
If you are truly serious about VP, you need, well, an outboard video processor. The most affordable yet still effective unit is pretty new, called the DVDO Edge (uses Anchor Bay).