Hydrojunkie is right. Fullers or Fine design both have top of the line hardware. Propshop has great props , if stickershock is a problem , pick up a Octura. OffshoreElectrics has an excellent article on sharpening a prop. It's realy not that difficult.

As far as size? 21" , 22" would get you in the ball park.

Which prop to buy depends on the motor you plan on running. Which motor depends on how much you want to spend.
What kind of motors do you currently have? What kind of Batt charger do you have?