I would look at some of the Entanet resellers, they are the current favourite place for people to go at the moment.
Check out dslzones reviews, most of the top10 are Entanet resellers (titan, adsl24, aquiss etc.)
My parents have ADSL24 at their house and it has been very reliable whenever I've been home, cost will obviously depend how much you intend on using it during peak times, although with the very generous off-peak data caps any large downloads shouldn't really be a worry.