I agree, start small if you choose to go that route. First things first, start selling. I'm sure if you walk into any business and tell them you want to help them sell more they'll be happy to listen to what you have to offer. One theory about working for someone else before starting your own business is that experience gives you an opportunity to learn and make mistakes on someone else's dollar ... plus learn from their expertise.
I maintain a directory that includes medical supply businesses
Plus maybe look at some of the other internet directories and do some searches. That's one thing about medical supply, I think there are more than a few. Something to consider as well, it's a competitive area where margins of a penny can be the difference between a sale and not.