Mate, I have a G&G ump and the range is pretty good. The ump may be out of your budget but mp5's are roughly the same in airsoft terms.
Just beware of the mag length. Going prone with a 10 inch long mag is an art form.....but you'll soon get used to it. Just remember though as you don't wona break anything first time you hit the deck!!!!
G&G are quality products too. Don't get a cheap make for the sake of it...I've been there done that and the gun is in pieces at the bottom of a box after 1 game.
Spend as much as you possibly can as you'll only end up spending more in the long run.