Ok so far I think I'm going to go with a CYMA M14 SOCOM as I like the external look of it, don't mind a little extra weight for the Full Metal and it looks like regardless of what I'm getting I'm going to be upgrading the internals.
What are the major upgrades to increase range and accuracy that I should start with? It looks like fixing (or replacing?) the seals (I'm assuming to increase gas efficiency and power) should be done first and then the gearbox and barrel. I left out upgrading the hop up as there are differing viewpoints and I don't know enough about upgrading to make a judgement call myself.
Also what is the part availability (and compatibility with other brands) for the CYMA M14's they seem to be popular but I've also heard they are a Chinese knockoff brand and that some knockoffs are hard to find parts for.