another thing that ive started to recommend those who want to leave vm and go adsl is to ask your neighbours what kind of service they get and if they get speeds that are fast enough.If you to far from the exchange you may get a lot less than the 4 meg you get now also there are often hard caps on cheaper services Talktalk for example have a hard cap of 40 gig per month.Orange is unlimited upto 8 meg for £20 quid.Probably the cheapest unlimted service is with sky but then of course you have to subscribe to sky tv.
Dont expect to be able to find an good fast speed with high download cap for nothing we all want that
you did say moderately heavy broadband users so to find a package for less than 25 quid with a good high cap and then get cheap calls abroad and included calls in the uk for less than the VM packages isnt gonna be as easy as you may think