I've looked up player kills in the forum's searches and found nothing that's similar to what I'm proposing. I don't think the pk system we have now is very fair. We are limited to a 1 or 2 level range from ours, and still that person must be similar in dks, otherwise it makes pk's a challenge to obtain.
What I suggest we do, is do the pk system by toughness. In the HoF, there is a toughness area that tells you how you compare with other players. I think that the pk system should leave you available to any forest sleepers that are within 100 points higher than your score, and 25 lower. In scenario terms:
A level 12 chuunin may be sleeping in the fields one night, and I, after a dk, being level 1, would have the option to fight him. The match would be fair overall, atk points relatively the same, as well as defense, and the amount of pks that a person could obtain increases severely. Also, I'm pretty sure that more pks will occur at higher levels, rather than having a pk frenzy at Jounin and lower.
It's not a bad idea, fighting would be rather equal, and it would interest others into wanting to use their pks for actually pking, rather than taking a trip to Heidi's.