As Sadaiyappan said, the PRO sticks are quite a bit faster.
I'm kind of a PSP junkie and have accumulated and tested quite a few sticks since I got my first fatty. Make sure you buy your stick retail. If he's just using this for games then a 512 meg stick is more than enough and you might as well plunk down the full price for a nice SONY branded stick if you're buying that small. When you get into the bigger sticks Sandisk is the best bang for the buck. Stay the hell away from Lexar even if the price looks nice. They are slow as shit.
As far as deals go, you may as well sign up for CAG and just sit back and watch. There's at least one memory deal a week.