VDSL/ADSL and perhaps 'cable'.
1000mbps ethernet ports
Automatic fallback to a USB 3G stick.
One possibility appears to be the Asus DSL-AC56U which both Origin BB and Currys sell for £89.99
Is there anything else I should consider?
If at all possible I would like to move from an ADSL ISP to an FTTC ISP without being physically present.