I'd like to get an M-14 and turn it into a DM rifle. I've seen and used a G&G M14, it was an excellent gun for the price. I find that even a person on a budget can wait a while and save up for a "better" gun. But better is a very subjective word so, it's mostly up to you and what you want.
I've never had a problem with any Echo-1 gun, but the G&G would be my recommendation.