Form plug in for multiple company locations

As the other guys point out, ReachForce and DemandBase are the true equivalents of what you're seeing on that form. But you weren't totally clear about what you're expecting to be filled in for the lead, so let me add...

RF and DB and their competitors are enriching the form data with a bunch of firmographic information (which is why they cost anything at all).  If all you need is the surety that the lead has filled in an easily identifiable, extant entity -- allowing you to fill in their website and geographic location automatically, for example -- you can use Google Places Autocomplete for free, as demoed here: MktoForms2 :: Googe Places AutoComplete​. Of course, while Places will guarantee you a real and singular "place," you'd have to do further enrichment of that place separately.  It's not going to tell you their annual revenue, for example.

P.S. One other thing: I have found SmartForms to be really problematic if you have other custom Forms 2.0 enhancements. Theirs is a pretty questionable implementation that doesn't play well with others.

We use DemandBase's Marketo forms connector for this.  Very similar to ReachForce's.  Except you're prompted to select your company while your entering the company name (vs. after you hit submit).  Try it out here (just don't hit submit): Contact Us | Avanade

@Kim Gandy​

I would add to Greg's point that this would be quite difficult to achieve as a custom development, Fortunately ReachForce Smartforms are quite reasonably priced and their data is top notch.