How urgent is the need for it? Can you save up a little more? As others say, £2.5k is pushing it for a rig to cover the size of band you refer to, assuming you want to buy new. Agree with advice to keep it all separate - passive mixer, speakers, power amps, etc. The other advantage of doing it that way is that, rather than the band owning the PA jointly, individual members own individual items. So if someone leaves, you don't have all the bother of agreeing a price to buy out their share, etc (bad idea to sell a rig and split the proceeds - you lose too much money doing that). They just take their item with them and the new member(s) replace it.