It is my opinion that those temps are acceptable but, you should invest in an aftermarket heatsink/fan for your CPU. That with some good thermal paste like artic silver should bring down those temps.
Also, it would be a good idea to get some more fans. The fan on the side of your computer should blow in then the one on the back should blow out. Personally, i have modified my case to accept a 120mm fan on the side (~50 CFM) and then i put two fans on the bak that blow out. Finally i have one PCI fan that plugs into a pci slot and blows air out as well. I just think that you should have the same volume flowing in as you have flowing out of the case.