1/8 jacks and sockets certainly are available from good suppliers but aren't often supplied with transducers or pickups. I have often fitted them for customers who don't want a standard jack or on smaller instruments. I installed one on my current classical and also on the F5 style mandolin I used to have. With suitable cables and the usual precautions there should be no problem.

I know this is purely aesthetics but I don't think I could bear a soundhole pickup across a beautiful acoustic.

Peace

moo