Buying own Modem

We are using Comcast Business Starter Internet for our office and planning to buy a modem instead of leasing it.

I'm checking Comcast's website. It's showing the following modems are compatible for our service.

1. Arris/Motorola     Retail SB6120 SURFboard DOCSIS 3.0 Cable Modem
2. Arris/Motorola     Retail SB6121 SURFboard DOCSIS 3.0 Cable Modem
3. Arris/Motorola    Retail SB6121 SURFboard DOCSIS 3.0 Cable Modem
4. Cisco                  DPC3008
5. Cisco                  DPC3939B
6. Netgear              CG3000DCR
7. SMCNetworks   SMCD3G-CCR

Which one would be better for a small business?

When I search through forum, SB6141 seems not support Comcast Business. Then why this is listed in my search?

Thank you.