OK - to try to put all in one place what I've learned over the last couple of days.
Dlink. I've not bothered looking. Given what the last few Dlink ADSL routers i've seen are like, I'd not consider it anyway.
Zyxel Prestige 870. Zyxel disti in the UK is not stocking this nor will they consider doing so until BT officially allow third party routers to be used and provide facilities for manufacturers to test their systems and work otu suitable settings to publish alongside the gear. The UK disti offered to source one for me on a strickt "no returns" basis with no guarantees and definitly no support. I'm not going to go there. Had BT enabled my local exchange I might've taken one to test out on my own line. I look forward to wires-only officially happening and have no doubt the P870 will be just as good as the P66x range we've been using for ten years on ADSL.
Thompson. I have a "Speedtouch" here we bought for line testing on problem cases as we were informed it's the router BT themselves use. But the UI is so dire, I'd never recommend one to a client. One of the networks we resell supply them as managed devices. Well, that's up to them!
Vigor 2750n. The UK disti say it should work with FTTC and offer a How To Page (see link) . I'm not clear if this amounts to them guaranteeing it's suitable or merely offering some assistance. http://draytek.co.uk/support/kb/kb_vigor_v2750_setup...
FritzBox. I have one customer using one but his initial attempts to get it working were unsuccessful, and he reverted to using it's PPPoE wan port and the BT router. I have forwarded him the additional info found here, but can't say if he'll try it or not. I also forwarded the caveats about the adverse affect of the line tests FB ran.
IN ANY CASE of course, it should be understood BT do not recommend and will not support anything other than their own supplied modem connected to the VDSL service, for the time being at least. I can only note that the GOOD news is they provide a modem and NOT a full router, so at least we're still in control of the firewall, etc., processes on our own kit inboard of the modem. Small mercies...
Thanks to all who contributed.