Is My 760 Going to Bottleneck?

I have a stock HP mobo by Pegatron with an AM3 AMD Athlon II x4 @ 2.4ghz. Is a 760 going to bottleneck on this board? I want to know what I should direct my money toward. I really want a new card but idk if it would be worth it on this system, anyone know?

Ya just make sure you have a good enough power supply and 4gb or more of ram and it should be fine.  I would recommend a blower design cooler though to get the hot air out of your case like the EVGA ones

I really want the Direct CU II model by Asus. I have 8gigs of ram and a 750 Watt Seasonic PSU.

As long as your case gets good airflow then that'd be a good choice, if your case does not have good airflow I'd get a blower.

I custom mounted 2 extra 120s on it. One behind the front panel blowing inward, one on the side of the case blowing inward. I also have my PSU with it's fan blowing outward. No rear case fan, though. Think that'd be ok?

I messed up in the original post, I meant 760 not 660. I was looking at a 660 at the time but that's not what I meant. Does this change anything?

No the gtx 760 will be a good choice with your setup as you said you have a 750 watt psu and decent air flow