In-hole one? You mean a little microphone that you stick inside your guitar? No experience with those, but I think it'd sound pretty muddy. Just take your guitar to a guitar shop and have them drill a hole and install a pickup. If you get an active pickup, get the kind with a cartridge you pull out of the side to replace the battery. Having to loosen all your strings to get your hand in the hole to replace the battery SUCKS.