1. Do you need any more information to help me please?
2. Do I have to overclock or change anything else; software or hardware?
3. I would like to use MSI Afterburner if that's compatible.
4. Will I get a bottleneck?
You didn't actually tell us what you want to do. I assume it's to overclock your GTS 450 though. I don't have time to explain it, but I might link you to an old thread of mine. Your CPU and graphics cards should balance each other nicely though.