Sandy bridge motherboards don't have on-board graphics, the GPU die is fused inside the Sandy bridge processor itself. You can get a H67 chipset based Sandy bridge motherboard within 6K. But let us know what is your budget for the CPU motherboard combo. Then we can suggest u in better way.
In case of AMD, the best onboard graphucs within 6K will be any 880/870 chipset based mobo. They have ATI HD 4250 graphics card with dedicated 128 MB of DDR3 memory.