To add to this, I'd suggest adding an 'email me' option if things are slow on the site. Waiting on a website longer than 20-30s is painful but receiving a well formatted email within 10mins (with the same info) can still feel like magic.
I'm working on something with the same concept but for a different market. There's no way for me to tap into 3rd party databases (for now). I'm setting it up so the results will be added to your own personal search-page where (only) you can view them after x-time. From there you can choose to view more details and/or close the deal. Not as fast as live-search, but I'm communicating it from the get-go.
It's a stop-gap but could work well in this case.