Crucial or G.Skill RAM would be good. Make sure it's 204-pin DDR3 1333 MHz RAM.
About the SSD, OWC is currently the best for Macs, though they have some firmware issues. I'd wait to buy an SSD until Intel releases their G3s (going to be much cheaper), or OWC adds some official Mac support into their firmware. This should all happen within the next 3 months or so anyway.