First you need to pick some airsoft guns. I would pick a sniper rifle, a pistol, a cqb, and some extra mags.
Step 2: CQB
In a close quarters situation like something inside, i wouldn't take a sniper. Use a sub-machine gun and a pistol. You might want to have an automatic gun on hand also.
Step 3: Outside Play And Sniping
If your outside or fighting over a long stretch of land you might want a sniper rifle. A good range for FPS would be 350 to 600. Mine is a 400 and it works like a 600. You should consider the maximum ft of effectiveness. I have a 200-250. You should also have a CQB and a pistol with extra mags.
A grenade is a good thing to have on hand in a close quarters situation. They can clear an area, eliminate threats, and some can blow down doors. All you need is these: 1. Easter egg 2. Bottle rocket without the stick and extra long fuse 3. BB's 4. Screw driver. First, put a hole in the top of the easter egg for the fuse. Then fill the bottom half of the egg with BB's. Put the bottle rocket through the hole in the top. Then put both halves together. You will need a match or a lighter to make it go off. I am not responsible for any injuries or death. I am sorry for whoever made these images but i had to use them. They are great.