PlusNet click here Their £14.99 package supports unlimited downloads as long as you`re not abusing their "fair use policy. You can opt for a one off payment of £11.75 and get a monthly contract to avoid being tied in for 12 months. Free modem & Setup with National Rate telephone support.
Otherwise Pipex click here Their cheapest package is limited to 1Mb free and charges you for additional useage but it`s not excessive. They also do a telephone package that is very good for £4.99 per month.
I use both the above and have no complaints about either. Technical support is excellent from both. If you want a referal to either drop me a personal message using the envelope.