If you marry and petition to adjust your status, there shouldn't be a problem. If you play games and delay, you will either have to leave the country to avoid going out of status, or you will overstay and risk becoming subject to deportation proceedings during the period of years you apparently plan to overstay.
Your sponsor needs sufficient income and assets to sponsor you, but if your fiancé does not personally meet the criteria he can get a cosponsor.

