Go old-school. Get a carry handle (
http://www.evike.com/products/26175/) and a rail mount for it (
http://www.evike.com/products/25626/).
Or pick up a high-rise mount (
http://www.evike.com/products/53634/)
On a related note: I'd have to be pretty darn desperate to pick up an optic online unless I had handled one of their products in person. This goes double for magnified optics. Bad glass is just, well, bad. Like anything, you generally get what you pay for.
If you've already played with a magnified optic, feel free to totally ignore everything below this:
I'd strongly suggest seeing if somebody you know has a 4x magnified optic that you can try out before you pick one up. Chances are, you'll end up deciding not to buy one. AEGs are relatively short ranged. My personal experience (and yours may very well be different) is that anything over 2 or 2.5x is more trouble than it is worth at the ranges that airsoft is effective, and generally a non-magnified reflex optic is a much more useful tool than a magnified reticle when used on an AEG in an assaulter role.