Motherboard

as you didn't know i3 and i5 is are different from pentium and core 2 series cause they have a different lga 775 or i3 and i5 uses lga 1156 or second gen i3 and i5 uses 1155 so you should choose one lga of them.

One motherboard will not do all those things. Pentium 4 and Core2 use LGA 775 boards. First generation i3 and i5 use LGA 1156 boards. Second generation i3 and i5 use LGA 1155 boards.

LGA 775 boards are obsolete and no longer have processors made for them although you can still buy them. They used DDR2 mostly. The LGA 1156 and newer 1155 boards use DDR3.

All of the graphics cards you listed are obsolete.

i know but a gtx 295 beats the radeon hd 6850
is there any lga 775 ddr 3 motherboard?
ill go with core 2 duo

When the GTX 295 was released in 2008 as the fastest card made and it was $500. The HD 6850 was released at the end of 2010 as a mid level card at $150. You really can not compare the two. The HD6850 is much newer technology. You also can run a HD6850 on a good 450w power supply while you need more like 650 watts for the GTX 295.

LGA775 is a dead socket. Meaning it is obsolete. There are still a few motherboards that can be found for it. Some are DDR3. The CPUs themselves are quite expensive compared to newer more powerful CPUs.

so what motherboard should i take and what is the cheapest best cpu
btw
is the radeon hd 6850 cheaper than the gtx 295?
which one should i get

Unless you need to replace old tech, there's no point in buying anything from Intel that isn't LGA1155.

There are plenty of motherboards less than $75:
http://www.newegg.com/Product/ProductList.aspx?Submit=E...

3 CPU's under $75:
http://www.newegg.com/Product/ProductList.aspx?Submit=E...

6 CPU's $75 - $100:
http://www.newegg.com/Product/ProductList.aspx?Submit=E...

11 CPU's $100 - $200:
http://www.newegg.com/Product/ProductList.aspx?Submit=E...

Any of these will be faster than equivalently priced LGA775 parts.