What airsoft gun brand has the best internals?

I know that the exteriors are important too, but I'm more worried about the internals lasting a long time. Are there any middle end AEGs with really good internals? If not should I get Clic Army, Tokyo Marui, or ICS based on internals. fps doesn't matter that much to me. I don't want to spend more than $300-$330 including stuff like money left over for extra mags, bbs, goggles, etc. Preferably from evike.com or airsoftgi.com.