[uripyores]

I've been using Virgin for 8-9 months so far, I haven't been cut off once yet. The deal I've got right now is only 512 but at the end of the summer they are putting it up to 1MB and it costs me £17.99 per month with no long contracts. They do 2MB for £24.99. [free activation & modem]
Not sure about the router support though.

Virgin.net

Here's a guide for UK ISP's