Yet another pedal option would be Crank Brothers (specifically Eggbeater, Candy, or, if you can find it, Quattro) with the three-hole cleat.

Computer? Really depends on how much you want. I stayed with a wired Cateye for a while, then got a Blackburn Neuro primarily for HR monitoring. I have no plans for a power meter and not enough interest in datalogging anything else.