Setting up a group bank account for a server project

Me and my friends have been working on a server project on GMOD, we intend to sell stuff for this server and would like a bank account for this to go to.

We've been working on this for approx 3 years, and I'd like to be able to give the founding members permissions to use the money on the account for purchases for the server. Each purchase should require the permission of either the owner or a group agreement. The payments will mainly be for server upkeep and additions that would cost money.

How would we set up this bank account and with which bank? We are all based in the UK but paents may come internationally later on.