If you would like to stay in the property 2+ years then it is best to try to get as much information about the Owner and the property before you rent it. For example, is the Owner in the military and plan on coming back in the next few years (or have they just left on their deployment and will be gone at least xnumber of years).
Is the Owner a seasoned investor and has no interest in selling the property any time soon? What are the Owners plans for the property within the next couple of years? All of my Owners would love a Renter like you that would execute a multiple year lease!
My company has a mixture of all those and I can tell a potential resident the chances of being able to stay long term in a property. Of course, you need to make sure the property isn't in jeopardy of foreclosure either!
If the State of Florida Supreme Court approved lease for residential properties is used, then yes, it specifically states that the lease period can be no more than 1 year. However, some (like me) use a lease drafted by an Attorney which can be for however long we agree it to be but if longer than 1 year, it does need to be in writing and signed by 2 witnesses.