What xfinity modem should I buy to work with my Orbi RBR50?

[LisaMc]

We're ditching Verizon Fios triple play because of compatibility issues with Verizon and Orbi.  Going with Xfinity for internet and will use live streaming service for TV.  We have an Orbi RBR50 with two satellites for our home with two levels, plus a below grade, finished basement.  Which Xfinity compatible modem do you recommend we buy (NOT renting from Comcast) to work with our existing RBR50?  Is there any compelling reason to spend more for the Orbi modem/router instead.  (Again, we have a finished below grade basement and two upper levels to our home.)

[SW_]

I've been using SB8200, which is one of the approved modems by Comcast Xfinity.  It's working well for me.  You can aso check the review comments on Amazon.  Good luck!