You would want to look into Buissness Grade Broadband. Would be worth while contacting BT as they tend to handle broadband for schools and high-end buissness. My dad works for them and there are variations higher than 25mb.
Use that form and search around. there are different prices depending on your needs.
For a 2mb/2mb connection it's around 2mb, but it is worth contacting a supplier and asking about a dedicated Internet server package.