I don't think the fact your using a BT line makes any difference.
There's a vast range of units available. Very few people have experience of more than the one that they use and so cannot make comparisons (reviews from your facourite PC mag best for this?).
Otherwise go onto something like click here and look at the buyer reviews listed under each model.
Personally, I've got a 3com 3CRWDR100A-72 bundled with a wireless card from ebuyer. All works fine and easy to set up.