Need advice on renting a home

So me and my fiancé have been applying for homes for the past couple months. After so much money wasted I'm feeling defeated. His credit isn't great at all and mine is decent, we both make great money and have proof of great rental history for the last two years but it seems we just keep getting the run around or straight up No's because of credit (which we are both working on). Or my fiancé having owed a shady apartment 7 years ago. I say shady because they have yet to provide proof he owed them what they are claiming and has changed management companies and names numerous of times since he's lived there. Our family has out grown the apartment we are living in and a house is so needed at this point. Any suggestions on how to win over some of these landlords? Or property management companies suggestions?