Cable Modem & NAT

Am I loosing my mind, or are there no cable modems with
NAT firewall? I know 2Wire makes a DSL with NAT, but
that is the closest I can find.

My friend has but one computer and will be getting
Cable. I said I would help him get his set up, but I
really cannot see having to buy two products (modem &
router) when you would think the industry would have
combined them by now.

Any suggestions?

Thanks!