I have seen in vBullitin forum those who are having 500-1000 members and only 35 to 50 members online at a time consumes 15GB Bandwidth. You are offering some download to members which also consumes the bandwidth.
So I recommend you should go for Dedicated Hosting which gives you 2500 GB bandwidth and 160 GB Disk space & eUK Host costs only £79/month for it. By that you will get full access to your server, 100Mbps Dedicated Network, Free Software Updates and 24x7x365 days Ticket, Live Chat and Phone Support to resolve your problem.
