Your motherboard will handle it, but not your 250 watt power supply. As far as I can remember, Acer just uses regular ATX power supplies with the exception of their slim line models of course.
At any rate, this power supply is very good and has more than enough power for that card. It would also run a HD 6850 card if you wanted to bump up a little more. Either would work well with the Core i3-2100 processor you have. I would also check around at Amazon and other sites that sell these. You might find a better price.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371033
If you opt for a different power supply, just make sure it is at least 80 Plus Certified, and has at least 28 amps on the +12v rail. If it has no certification, avoid it no matter what the maker claims.