ultimately your best bet is to check with the providers you have on your short list. Samknows is fairly up to date with LLU operators (email them if not) but it doesn't take long to check 4 operators number checkers to see what's available.
MaxDSL - goes as fast as it can and doesn't read the line checker first.
Are your kids pirates ? Limewire, Bearshare, Kazaa, BitTorrent, eMule are all tools of the trade.