A router is a Router. I guess You could get any cisco Ehternet Router to work. usually the router supports automatic DHCP lookup so it should be fine. keep in mind that CISCO usually tailors to the business crowd, so they might not offer NAT, in that most of their customers use T1s and such, and do not have to worry about going through a single ip. Then again, they might support it.
Basically, make sure it has these things:
-NAT
-DHCP auto lookup
Good luck