King Arms FAL by far the best AEG I've used in a long time robust, accurate and really do not need any upgrade..........Plus it's different than the rest of the herd (M4, AK's)
http://www.airsoftcanada.com/showthread.php?t=77589 or a Galil they are short enough for CQB yet long enough for outdoors
http://www.airsoftcanada.com/showthread.php?t=71841