Working with a IMO/FMO

[regularAgent]

I had been with a 2 corp, NYL and massmutual and 3 different agencies and I'm fed up with them, so I'm going to work independently and this had made me feel that I was right, please can anybody tell me, what the different in working IMO and FMO, because I will need one of those.
I will do my due dilligence but How do I choose it,and where to start looking if there are a lot of difference in between them.
Im selling Life, annuity, UL, health, and will do some medicare if is good.