If it's an enterprise product you've already conceived, hopefully you've built enough of a network in that space to be able to get introductions to the sort of person interested in selling into it. The main thing to vet them is to understand how they plan to cope with not having inbound leads, a marketing plan, any brand recognition or even a complete product at the start of the sales cycle. To a certain extent enterprise salespeople can self-select themselves out of that sort of opportunity if it doesn't suit them; they have other routes to big money through conventional jobs.