Several combined devices available. Though once unlocked, the Openreach device can also perform both functions (modem and router).
Easier perhaps to look at the VDSL CPE chipset solutions available.. Almost all devices have a multi-port ethernet switch controller for routing functionality..
- Broadcom 6368 (e.g. used in Huawei HG612, Alcatel Cellpipe 7130, ZTE ZXDSL931CII and the ZyXEL P-2812HNU-51c)
- Lantiq VRX268/VRX288 (e.g. used in ECI B-FOCuS and Fritz!Box 7360),
- Ikanos Fusiv Vx180 (e.g. Fritz!Box 7390, Sagemcom 2764)
- Metanoia MT2201/MT3201 (e.g. Draytek 2750 and Draytek 2850)
There are a couple more VDSL2 CPE chipsets. In theory these should work with BT Profile 17a spectrum, but no devices yet available in UK, sfaik..
- Ikanos Accelity (2Wire/Pace 3800HGV)
- PMC-Sierra PM4380 (2Wire/Pace 3801HGV)