kwa m16br or ca m15 a4 rifle?

im looking to get an good m16. i have narrow my choses down to the kwa m16 battle rifle
http://www.airsoftgi.com/product_info.php?cPath=139_24_202&products_id=3900,
and the classic army m15 a4 rifle http://www.airsoftgi.com/product_info.php?cPath=139_24_91&products_id=4924.

i am looking for a gun that is a good field weapon but can also be used as a good mid-range sniper rifle. Im not really looking for a cqb gun. i was wanting to get the airsoft gi g4 a5 dmr http://www.airsoftgi.com/product_info.php?cPath=139_24_302&products_id=5319 but my friend said that i shouldn't because they have bad internals. i really like the kwa m16 battle rifle but haven't been able to save up the money for it and i just want a new gun. then my friend suggested the classic army m15 a4 rifle but if i get one im confused because i don't want to accidently buy the wrong type of the m15 a4 because on gi i think they mess up with the length of the rifle and said it the carbine length.

which of the guns above have the best look, internels, and over all function. if anybody has had any problems with any of the guns please tell me. im open to recomendations of other guns too just give me a link to it

About the G4 series, I said they use G&G internals, which I hear have a huge list of problems, many with their hop up, and also the fact that they use zinc for their gears, an extremely soft metal.