i reccomend to really get the 955, its an amazing cpu, but just incase im wrong, theres another thread i made asking whether the 965 is an overclocked 955, and whether the 955 is an overclocekd 945.
But best bet is to get the 945 if you cant get an 955.http://www.amazon.com/AMD-HDZ955FBGMBOX-Phenom-3-2GHz-Retail/dp/B002TQYUAE/ref=sr_1_1?ie=UTF8&qid=1314556590&sr=8-1
here is one i found for only 2 dollars i think over the 945.
The amd athlon isnt bad...
but i wouldnt get an athlon tricore if your gonna get an athlon, go for an athlon 645 or a 640 or something.
Heres a comparison betwene an athlon tricore 455 and a 645. http://www.anandtech.com/bench/Product/202?vs=188
in most cases the 645 does beat it, but the 455 isnt far behind.
Another comparison is the 645 between the 955.http://www.anandtech.com/bench/Product/188?vs=88
you can see that once again, the 645 isnt that far behind, but the 955 does beat it in every single thing. I may have mised one but yeah.
i also have a 6770 (same thing as a 5770 but i got it cheaper, like 75 quid or something) and it goes so well with the 955. I love it