It depends. The Phenom II X4 955 system will perform better with CPU related activities, and the AMD Athlon II X3 435 with gaming activities. It depends on what you plan to do. Otherwise, you could go for an AMD Phenom II X4 945 and HD 5830 if that fits into your budget.
If you get lucky and unlock the CPU you will turn it into an x4 B35 w/o the L3 cache. Maybe 4/5% slower than a 955 in gaming but to be honest the Rana can do 3.3/3.4Ghz on the stock cooler depending on ambient or 3.6/3.7Ghz with a nice sink.
The 5850 will do quite fine even if you do not unlock, I play games sometimes with only 3 cores to keep temps down @ around 3.8/3.9Ghz and I am VERY pleased with the results.