I can host but have no idea how to enforce any kind of "semi-public" build scheme short of sorting people into a no-building minigame and then giving everyone in BLBC the admin password. I'd rather just cordon off a section for you guys and let everyone else build wherever they want.
Feel free to post ideas and useful mods here. Preferably mods that will directly help with hosting, moderating and building, I don't want to install 3 different sniper rifles. You should probably tell me what maps you want too.
Also it goes without saying that if I'm hosting the server you guys actually need to use it. You should probably agree to some period of time when you can all meet and work together. Stuff has a habit of not getting done when there's no communication about what form the build should take.