I'd second the choice of air integrated for a beginner. I guess it all depends on how "tech" you want to go and how much you want to learn about dive planning. If you're not going to do any cave or wreck penetration, the "bottom time remaining" feature of an air integrated computer is probably a good tool for you and will take a lot of the guess work out of your dive.
On the down side, it also takes out the brain work. You need to know a lot more about dive planning than what is taught in a basic O/W class, in case your computer craps out mid-dive. It's happened to me, and I was glad I already had a plan and a backup (dive watch).