Do you need a new router? Why buy it from the ISP?
I am a fan of AVM Fritz!Box products. Currently, I am using a Fritz!Box 4060 on my FTTP connection. My existing DECT phones connect to it and to my VOIP service with AAISP.
There is a very good deal on a well-known German site for this model at the moment. It can be imported VAT paid. Ignore all references to it being a German model as all Fritz!Boxes have menu-selectable languages. It will arrive with a German plug which needs an adapter.