@lost1317 did you wrap up this project? It's on my to-do list, too.
Hell's Bay buys their carpet from Home Depot.
TrafficMaster "Elevations" line. They use DAP Weldwood contact cement to apply. I talked with Tom Gordon about tips and tricks for installation. He told me the Skiff Shop uses a contact cement spray on the carpet and the DAP under the gunwales. I can't remember the name of the spray he mentioned. He also said they start from the bottom edge and work their way up. I do not know if they try to template or not. I won't quote the price he gave me because it might have changed, but it was a great deal just to have those guys take care of it. Granted, you might have to wait in line a while.
I stripped my carpet out in 2018 (
link to thread) and have had installation of new carpet on my to-do list for almost two years. Limited free time means I'm not bothered enough by the lack of carpet to prioritize it over getting on the water. The fish don't care if there's carpet under the gunwales, so I just keep covers on my fly reels.