If you want and Uzi get an Uzi; not a Mac-10, Cobray or some similar knockoff, they are not worth the money.
Stick with the open bolt guns. The closed bolt guns just plain fire to fast. Yea A cyclic rate of 1500rpm is cool but its way to fast to control in a gun this size. The standard 600 rpm is enough, if you just gotta have more speed changeing the spring and buffer will gain you a few hundred rpm for just a few dollars.
If you wanna trick it out try a Para micro, small, compacted and come with piccatiny rails. The have a slightly different grip than other UZi's so you can use Glock 33rnd mags in them. Assuming you're getting a 9mm
In my personal experience Uzi's are the Ak of the SMG world. They may not be pretty or coolest but they work. They were designed to do a job and they do it very well.
P.S if you like Uzi's check out a scorpion machine pistol