There are lots of events of this type already in existence. The biggest are the Outdoor Retailer Shows every summer and winter, held in Salt Lake City. The PCT has their kick-off event that is a magnet for UL backpacking companies, and Trail Days for the AT was already mentioned. Trail Days this year attracted a lot of hammock manufacturers.
My recommendation would be to work with the smaller events and work in a guest speaker or demo event. The cost of administrating these events is offset by the retailers paying for booth space. This sometimes makes it hard for cottage manufacturers, who already pay for travel and shipping to get to the event.