Will again suggest TM next gen recoil M4. If you look there's a Canadian retailer with them for sale for around $650 or so. The price is high but after you tune up a $400 AEG you'll be getting up there anyway.
Literally needs no mods other than wiring for lipo in the stock (not even this if you want to use the Marui batteries) and a new spring and you've got your amazing performance, recoil, and bolt stop.
My stock Marui shoots around 340 FPS (fine for cqb around here) and it performs beautifully, even outdoors at my regular field with lots of long ranged engagements with 400 FPS shooting guns.
Last edited by brock0; July 12th, 2015 at 22:00..