building a DMR

I'd suggest a kwa sr-12, a new hop up rubber (unless kwa's are good because I dont personally know about their rubbers), and a new bucking. I've heard H nub buckings are good. Then with the full stock on the sr-12 you have almost any choice of battery. I'd go with a 11.1 lipo. I have had good success with firefox brand lipo's but its really personal preference.

I said the kwa sr-12 becasue then you dont have to go and upgrade all of the internals right away. And the ballpark number to make the perfect DMR is usually over your price range. Thats why i'd suggest NEVER to skimp out and always get the best. You will always regret getting something cheaper to save a little bit of cash right now as compared to saving up a little more.

Im sorry to disagree with you decision of the cyma but I strongly suggest you change your mind. Even with all those internals inside of it, it will still feel like a cyma. If your going to make a dmr you might as well not skimp out ANYWHERE. Skimping out to save a little cash here will bite you in the butt in the long run. I promise you that. I think most people would consider it blasphemy to go with a m14 style and pick anything but a TM. Unless you were going for one of the advanced m14 looks that cyma makes the body style for. But its still going to be cyma plastic. That's just my 2 cents.