Tryna get back into airsoft, what's the best aeg block 3 m4 for my price?

I work at a gun store and recently have really fallen in love with the block 3 m4s. I was wondering whats the best one I can get for around 350$? I have plenty of aeg m4 mags and a small chest rig so that's not an issue. Also, working at a gun store means I can get optics for the dealer price so that's not an issue either. I would be willing to settle for any MK18 esk rifle block 3 is just a general preference.