Core 2 quad? Expensive? thats like saying intel gma is better than a gtx 780
No they are expensive. I know, I bought Q9550. A used Q9550 is going to cost about $100. A brand new one is going to cost you over $200. In terms of relative performance, you're getting ripped off. You're only saving money by not buying a motherboard. You can get an i5 for $180 and it will destroy the Core2. An AMD 6300 is only $120 and it's more powerful and a better overclocker than a Q9550. Like I said, expensive.
Don't get confused with memory. DDR3 and dual channel are different things. Yes your motherboard supports DDR2 and DDR3 but it's not because it's dual channel. I could explain it but it's easier to just copy the line from Wikipedia:
"Dual-channel-enabled memory controllers in a PC system architecture utilize two 64-bit data channels. Dual channel should not be confused with double data rate (DDR), in which data exchange happens twice per DRAM clock. The two technologies are independent of each other and many motherboards use both, by using DDR memory in a dual-channel configuration."