Beggining Questions

Hello,
I have been considering three boxing for a while now and i have a few questions, i currently have a 20 inch monitor and was wondering if that was enough or if i should buy another cheap monitor, if i baught another i would like to put two of the characters on the smaller one i buy and put the main on the new one, i might also try to dual box because that seems easier to start out with but i am pretty sure i would like to three box. I was considering what classes to use and what race, it seems like most people go undead to prevent fear but i mostly play alliance. Is there any combination that is better then the rest. i might want to do two of one class and one of another because it does not seem like 1 class can cover all roles and three classes might be to complicated, my interests is mostly in having fun with light pvp and being able to do instances. please help, evaluating multiple combo's would really help. thank you