Ummmm no. I won't play with anything but my mp5, and I won't approve of a system that won't let me have it round after round after round. I'm not afraid of using another weapon. When the p90 and sig came out, I used each of them for a full day or two. I just didn't like their feel. Using the mp5 lets me get into the game. No other gun does it for me.
Think for a second. Would it really matter if too many people had, say, p90s instead of mp5s, unscoped m16s or sigs? The only weapon that people complain about whoring are scoped weapons, sniper rifles, and nade launchers. Possibly shotguns if you want to go a step further.
I'm not against somehow creating realistic loadout restrictions, but shoving an m16 in my hands and booting me out the door is a no-go.
With that said, I fully support your idea of giving each player a small amount of money (2-4k) and enable them to give the excess to people who want shiny, expensive sniper rifles and extra nade launchers. It would enable people like me to have their precious favorite weapons and do a good job of limiting the sniper rifles, ACOGs, and nade launchers.
But you see, that's not a preset loadout, it's just a restrictive loadout choice system. I absolutely hate the idea of being forced to use a weapon, and I believe that THAT [being forced to use a weapon, in case you don't follow my f0rked up grammar] is taking the easy way out.
One final thought: There's absolutely no way in hell that I would be as good with the mp5 as I am now if I only used it 1/5th of the time.