Hi Bonnie,
You should have no difficulities using a 2911 with that feature set for what you need.
Depending on how your internet circuit is presented, you may need to buy an appropriate WIC/HWIC.
For a 2Mbps circuit a 1800/1900 series would also suffice, although they will have fewer upgrade options in the future.
"Fast" depends on what your users will be using the internet circuit for...
HTH
Kevin