I would strongly recommend Intel for your CPU and Chipset. That is my preference though. I've had nothing but good with Intel system boards and processors. AMD is less expensive but in my experience the technology they are created with just doesn't seem to match Intel's Core 2 and Core i series. Also if you ever plan to use or explore Linux, Intel supports their drivers for Linux which is a huge plus.
As far as trusted motherboards...I would have to say EVGA, Biostar, and Intel. Biostar boards run very well. I have been using one that I bought almost 2 years ago as a light gaming rig.
When you say PCI Express 2.0 I assume you are referring to the x16 slots. I have provided a link to one that means your requirements.
EVGA P55V SLI Motherboard
It's about 95.00 USD on TigerDirect.com excluding the 30 USD rebate. If this doesn't quite do it for you. Poke around EVGA's website and also take a look at Intel's Extreme Boards.