Need plugin dev

Hi I need somebody’s opinion on something. Basically I kind of wanna make a gamemode on my server-king of the hill. I want to make it using custom bows, I found a plugin for this. However I also want it to be on a custom terrain map, which I can deal with. I want to make a menu when you do /kit that shows the kits and let’s you purchase them. I would want 5-15 kits. I would want pvp to auto disable and allow people to join for about two minutes. Then disable joining and turn Pvp on. Block breaking allowed, and auto restore using wr (worldrestorer) I would then want it to reward the player(s) by the amount of kills they get and give them exp for playing and killing. With exp they could get kits, and some kits would be purchased using in game currency. You get the idea. I’m wondering how hard this would be to do and how much it would cost to have somebody help me with it. Ty
Moar bows is the bow plugin