Personally I think the NHL cap should be in between the NBA and current NHL cap. The NBA cap allows you bird rights to go over the cap to resign your own players. It also allows you exceptions to add players when you are above the cap. AND if you go too high over the cap there is a big tax, and the tax gets even bigger if you go over the tax threshold for consecutive seasons.
Maybe they don't allow the exceptions to still add players if you are over the cap, but they should allow teams to go over the cap some to resign their own players. Otherwise teams are going to lose their identity players very often.
It will never happen with the attitude in the NHL, but it should. The NHL and NBA caps are essentially the same amount, but you just cannot keep enough of your players long term in the NHL. It's a shame, but the NHL is very concerned about parody. I would argue the smaller market teams would get a lot of extra money from teams that had to pay taxes for higher payrolls, but the NHL wants every team to be just about the same talent wise, so that's how they have setup their cap.
Shame because I think we are heading down a bad road here...