I had the same problem as you a few months ago, coming back into paintball after a couple of years out of it.
I suggest before you go and spend all that money on a new marker visit a few shops or tournaments and try out a few different guns.
As far as air systems go there all prettty good, so its down to how much money you want to spend!
Good luck with your choice!!!!!
P.S. I eventually went for an Angel LCD with Angel Air.