If an illegal alien has a felony but is paying for it with doing time and paying money and gets married to a US Citizen what could happen and can he ever be able to be here legally?

You must be aware that many times a felon will be deported after serving his time. I would seek professional counsel and apply for permanent residency if already married ASAP. thus if your time is longer than 3 years you can apply for citizenship. It is an uphill battle but get your papers in order ASAP.