i don't pvp, but i must say that this is a good initiative
furthermore, if it's a league setting, i agree with Aaronock on how skillful HPs and SLs can at least get a draw. Perhaps it would be wise to allow draw negotiations to be discussed by each participant before the match.
would be easily counted with the 3-1-0 league scoring system.
as for pots, to make it fair (and a proper zeny sink) i would say that we should limit those pots to NPC pots
ygg leaves and bgems should also be limited (probably in the same way -> 5 ygg / team and 20 bgems / team)
you should also ration out limits for other consumables such as red gems, ADs, etc perhaps?
as for prizes, i believe Tripp basically summed it up...
-w-