So basically, I wanna know if there's anything I should think about changing in this build, and what RAM I should get. Any suggestions for a cheap mouse and keyboard combo?. Please keep in mind the case, motherboard, and HDD are already purchased. Will probably be getting an SSD a few months from now and re-install Windows on that. Have at it folks!
I would get the i5 3570k. Your cpu is not overclockable.
G-Skill RAM's are very good. Both those models are pretty good. Just make sure you are getting DDR3 1600 1.5V RAM.
I would get any DVD-RW drive that is cheap. The ASUS DRW seems to be one of the cheaper but reliable ones.
Hrmm.. Too bad you already bought the PSU. If you wanted to xFire in the future, the 520W may not be enough.
The rest of your parts looks good.
Also, you may want to check out these other websites for better pricing: DirectCanada.com, Bestdirect.ca, or NCIX.com.