Want disc brakes, what to do?

factory or aftermarket? do you want to stay small bolt circle 5X4", or convert to big bolt circle 5X4 1/2"?

http://www.ssbrakes.com/commerce/detail/index.cfm?nPID=8556

http://www.scarebird.com/index.php?id=29
Would like to keep it simple, so small pattern would bethe way I guess.