Receivers and PJ
1. Ability to drive 4 ohm fronts
2. Component connectivity ( upscaling is a plus)
1. You will need at least a Yamaha 2500 or Denon 2805 to drive the 4 ohm fronts. Depending on how loud or how long you listen you might need to upgrade to an external amp.
2. If you mean upconvert (from component and svideo to composite) than any mid-fi reciever will do this (Yamaha HTR-5860 and up). If you really mean upscale to 720p and 1080i, the yamaha RX-V2600 is the only one out that will do this and it costs >$1000. Also note, that the DLP PJ you list is only 480p, so an upscalling DVD player or receiver wont help much.
For a front projector, you might check out the new 720P LCD models. The Panny AE900U, Sanyo Z4, and Epson 550 are all >$2000 and you can probably get last years versions (AE700, Z3, etc.) for >$1500.
I have the Yamaha HTR-5860 receiver and I am happy with its features and performance for the price, but I wouldn't expect it to handle 4 ohm mains.