Now i have :
Intel Core 2 Duo E6750
Gigabyte P31-S3G mainboard
RAM 4GB 800Mhz DDR2
Nvidia GeForce 8800GT 512Mb -> have already ordered a Gigabyte GeForce GTX 560 Ti OC, 1GB GDDR5
So im looking for the options for replacing my processor without changing motherboard, so what would be the best choice for me?
And Okay, while we're at it, is there any good options for replacing the mobo for reasonable price range.
The best you can get is a core 2 quad and the best of those is a Q9650. They're expensive, so your best bet is to find it used on eBay.
A motherboard /processor/ ram combo would put you in ivy bridge. The other parts can be transfered without issue.