You might know that Marketo now also has a form fill product, but some other interesting vendors to consider are InsideView, NetProspex and StrikeIron. ReachForce has also added some really neat new data integrations lately so drill into those questions with everyone - the data world is getting super fancy and there are some really neat integrations from a lot of folks.
I love the ReachForce guys - if you need real-time appending for fast reponse, no one beats them.