Yes Force 9 /Plusnet do come with good webspace 250MB methinks, of the top of my head. And like you say £21.99 [non restricted] is better than paying £29.99 for BT's offering.
And if your prepared to take a resticted service [in that you have a monthly download limit] but still have 512KB always on broadband, you can get it for £14.99 from Plusnet.