D.B.
I have used Hyland's Teething Tablets with great success. They can be dissolved in a little water & given to the baby, otherwise you just put them in the mouth & they dissolve. However, with his age, I would do option 1. Also at his age I'd be careful what you let him suck on. They can suck on a bottle/breast well but when food is introduced they often choke because they've not learned how to push food to the back of the mouth.
Also some babies are born with teeth doesn't mean they're ready for food yet. I would talk to her pediatrician for solutions to the discomfort.