Visa for Chicago

Hi Everyone, I am new to this site and was hoping that someone might be able to give me some advise. My fiance and I are both Irish and currently living in Toronto. In Jan Protected content visa will be finished here and we want to move to Chicago at that point, we will be married by then also. I am a college lecturer in the areas of teacher education and business and he is a senior billing analyst. We are both over 30, with no children. Neither of us have jobs lined up and neither of use have relatives over there. We have been looking for information on the type of visa we need and are finding it impossible to make any progress. Can anyone give advice on what kind of visa we need or where to start? Also, my fiances aunt lives in San Diego as far as I am aware she is now an American citizen, if she sponsored us 1)would it cost her money to do so? 2) would we have to be based in San Diego? Thank you in advance for your help! Aoife