Cisco Router Etherswitch Module Differences

Hi,

I’m trying to find out what features/limitations/differences exist between the Cisco Etherswitch Service Modules (eg: NME-16ES) and the Cisco EtherSwitch HWIC (eg: HWIC-D-9ESW).
Obviously the number of ports and the module types are different but what else differs?

I want to be able to put one of them into a 2851 router (IP Base) and use GLBP, NetFlow, NBAR and possibly even BGP at some point.

I know the router can do all of those things, I just need to know if choosing either of the above modules would affect what I can implement.

Thanks

Jordan