In the benchmarks I've seen, most games have the same FPS if you were to use the 6670 without Crossfiring with the APU. I would recommend getting the Intel G860 with the Radeon HD 6850. It will cost about the same, but perform a lot better.
The Pentium G860 is roughly equivalent to the Phenom II X4 at stock speeds, without overclocking. It'd be a solid choice on the Intel side, but if you wanted AMD, I think they may have the upper hand sub-$100.
The Phenom II X6 Six Core is only 90 bucks at microcenter, so if you want AMD, that'd also be solid. Honestly, I'd go with the AMD 6 core over a Pentium, but that's just me.
The G680 is better for it's price, though. You'll be able to get a better graphics card.
For gaming, the high end Pentium dual cores are equal to the i3's. The only difference is pure clock speed since games don't hyperthread well.
and I will echo what others have said, the A10 does not seem to benefit from dual graphics crossfire. I thik the onboard GPU is more powerful than the supported cards that get paired with it, so you end up getting bottle necked by the 6670.
A10 is a good budget gamer if you aren't going to get a card at all. Otherwise, I'd get a Pentium G860 (under $70 at amazon) and the best video card you can afford to pair it with. IMO, the best bang for buck right now is the XFX 7850 1GB which is $150 after rebate on Newegg. It's a good 50% faster than the 6850 and 75% faster than the 7770 for only an extra $20-30. Money well spent, IMO.
CPU: G860 3GHz -62 euros
MB: H61M-P20 -34 euros
GPU: HD7850 1GB -150 euros
RAM: 2x4GB -34 euros
HDD: 500GB -53 euros
CASE: Something cheap for -25 euros
DVD/RW: Samsung SH-22 -15 euros
Total: 373 euros
What PSU you suggest? Max i can go is 500 euros. But less the better(to 450)