Anyone using a Scheduling Tool for Forms?

Hi everyone,

For upcoming trade shows, we typically attempt to drive people to either our events web page, or to an event Marketo LP where we list a particular trade show we will exhibit at. Our goal is to fill up our sales teams' schedules with meetings, so we ask prospects if they would like to schedule time with one of our reps at that event. 

Does anyone have any recommendations for a scheduling tool that integrates with Marketo, and, possibly in our forms? The hope is once someone checks the box that that want to schedule a meeting, the available times populate and the person can make a selection.

Thanks for your suggestions,

Dave