I recently moved from FTTC with Plusnet to their FTTP Full Fibre 145. Excellent service/installation/price and performance. Their own Hub2 worked well with the FTTP, but I too, wanted to have access to an analogue voice port. Being a long standing Zyxel fan, I bought a DX3301-T0 and used one of its 2 phone ports to access SIPgate services; it works really well. So I can thoroughly endorse it.
If you're interested in the AAISP provider, they have excellent guides for various routers with their VOIP, including Zyxels....I used their guides to help with setting up my DX3301 with SIPgate.
And having said all that, and having used the router for VOIP, I've re-concluded I'm happier NOT to have an active analogue phone attached and now use the DX3301 without its VOIP configured. I do use Linphone via my pc for VOIP with SIPgate; that suits better, and also use a mobile with a TalkHome package.