Originally Posted by kalnaren
With that in mind, I'd recommend either a King Arms, Classic Army, or G&P M4.
You have quite a few different guns on your list. What specifically do you want? Don't know? Then go to a few games and rent until you find out.
Absolutely, just because you will get your AV does not mean you have to rush to buy. Research a bit, find out how you like to play, if you buy a gun with a 16" barrel only to discover that you enjoy playing indoors more then all you have done is force yourself to put out more money.
I am speaking from experience here. I absolutely love the G3 SG-1, so I bought it as my first gun. Turns out that its very long for me and didn't suit my style of play. So I ended up selling it for $200 less than I bought it for.
AR's are a good choice as there are an almost endless combination of parts and accessories. Take it slow, but an item and try it out before buying something else just because it looks cool. The accessories on your gun should compliment your style of play and make you more effective, not make you tired cause you are running around with an extra 8 lbs of useless gear on your gun.