Any cheap BDU jacket, oversized of course, will do the job for a ghillie setup. Glue/stitch your netting onto that and from there you can add your jute and vegetation.
As for what to roll with weapon-wise, thats really up to personal preference. If you're going to carry a side arm, have it on a drop leg holster. Army Surplus here on the boards has a really nice one that I've been eyeing myself:
http://www.airsoftcanada.com/showthread.php?t=12641
As for your primary weapon and carrying the ammunition it needs, that really depends on the role you'll be filling in the field. If you're more of a scout, then you can go light on the ammo and may not even need a vest or chest rig. What I'd personally do in a sniper role is get a good pistol belt (you need one anyway for your drop leg) and load up some mag pouches onto the side and back, so you can low-crawl and not have any serious snagging.
My $0.02.