I'm afraid I am not aware of any combo modem/router which supports DHCP option 61 apart from the Draytek ones
TP Link models & Billion models do - the DHCP option 60/61 is hard coded into the router settings (ie invisible) when selecting 'Sky ADSL' or 'Sky VDSL' as ISP.
OP,
I would just buy a TP Link VR900v2. Its an all-in-one unit reasonably priced (~£100), gives decent wifi coverage (certainly better than Zyxel models), uses a Broadcom DSL chipset and is guaranteed to work on Sky FTTC. On the VR900 you simply select 'Sky VDSL' as your ISP and let the router do the rest...couldn't be easier
