A&K m249 Vs KWA KM4 Tactical,?

Hell no I'm afraid. No offence intended but A&K are chinese. They are still one of the top brands of china however, they at all break much more often and will cost more. You're probably best in going for an ARES/STAR one. Even though they are chinese, they are built brilliantly and will last as long as your taiwanese/japenese gun. I have an ARES L85 It's very good. You will probably end up spending more on a cheap M249 in the long run than a more expensive one at the start, in both delivery and part costs that you will most probably need for the A&K. Non the less, It should be fine, but don't expect anything special.