As Alabama Airsoft's Residential Gear Whore, I can make a few suggestions, Ill make a list of a few kits that I currently run and the setups that i run for each gun.
I mainly do a Russian kit, but I've slowly transitioned into a broader range of gear. I love accuracy in my kits so I usually go all out, a lot of the stuff is not needed but is cool to have.
If your wanting to do a correct Marine kit for example grab you a molle interceptor, I wouldn't want one as they are very bulky.
Kit 1. USSOCOM
Rifle: Custom M4 with magpul parts.
BDU's: Crye Replica Multicam
Boots: US Issue Desert Tan Boots.
Headgear: King Arms IBH helmet, painted with krylon and has velcro on it, with night vision mount.
Plate Carrier: Cordura Land CIRAS with 2 replica plates and an assortment of pouches
Backpack: 24 hour assault pack with 2.5l hydration kit, 1 mag pouch on the back of it for friendly reloading.
Accessories: Zip Ties on the back of the vest
Kit 2: Russian Federation Paratroopers (VDV)
Rifle: Dboys AK74M
BDU's: Flora with Correct patches.
Boots: US Issue Jungle boots
Headgear: Flora Kepi
Body Armor: 6B13 Issue Body Armor with trainer plates
Vest: 6SH92 Assault vest with 3 day assault pack
Accessories: AK47 bayonet, soviet belt, collar pins, etc
Kit 3: Soviet Paratroopers
Rifle: Dboys AKMS
BDU's: KLMK Jumpsuit
Boots: Issue Jackboots
Headgear: Afganka or Panama hat.
Body Armor: 6B2(Coming Soon)
Vest: Lifchika
This is just some examples of gear that you can get, it's really up to you or what the game calls for. If your going to a milsim game I would go in heavy gear, if a local game I would go more high speed and not be so loaded down.
BDU's: Flora with
_________________
Dboys AKS-74
Dboys AK74M
Dboys AKMS
Dboy's HK416
Alabama Airsoft's Official Gear Whore.