the problem with G&G M14s, one there expensive, and two they have alot of propritary parts, including the mags. so if something breaks in it, it can be a pain in the ass to find a replacement part, and they are near impossible to upgrade.
TM M14s are much more upgradeable, easyer to find mags for, are just plain better quality, and much more realistic. They can cost near the same as the G&Gs, but generally on the cheaper side if they are stock.
EBRs are just a kit, but with a standard M14 the weight of a battery in the stock ballances out the weight of the barrel. so witout a stock in the battery EBRs are very front heavy. For practical reasons, as well as finacial stick with a standard M14.