[BennyBoy]

Do you plan on getting the gun just to plink? If you want to play an actually game you'll need a lot more money.

CQB: Get yourself a good set of goggles and face protection.
Field: Same as above but you'll also need good set of boots and a vest or belt.

CQB games are usually short so you can run with a spare mag or two in your pockets. Field games usually last much longer and you'll need to be able to hold multiple mags. Good boots will save your a broken ankle. Good set of goggles is the most important equipment. You want to make sure you don't go blind and you want to be able to see what you're shooting once things get hot and heavy. You'll fog up badly if you go with cheap goggles. Face protection is pretty important for CQB, don't want rounds busting your lip and teeth.

As for the right gun for you, same question as above applies. CQB you'll want shorter and more manageable guns, outdoor you can pretty much do whatever you want. I ran a Scar Heavy for CQB and bitch is cumbersome and heavy. Don't get me wrong though, I tagged a many OpFors with it and felt like I was over powering people when in the open. My P90 however has a much longer trigger pull but the length of the gun makes shooting out of cover and window a breeze. Almost like I was cheating!

The gun that comes most highly recommended as AEGs go would be the Kings Arm M4. The M4 platform has collapsible stock so you can make it nice and compact for CQB or longer for outdoor. Very versatile platform with lots of accessories and upgrades. Magazines are common and cheap as well, most vests with integrate pouches will hold those mags too. The 416 is just an update version of the M4 but HK so has similiar properties. M16 is a very large rifle and not as versatile as the shorter M4/416.

If you gonna get an AEG rifle, pistols are pretty darn useless. So do yourself a favor if you're on a low budget, use that money to buy essential kit ie; eye protection, face protection, vest, foot wear and extra mags.