If he spends equal time with each parent, make sure he spends one night more per year with the parent with the lower income. That parent will become his ‘FAFSA’ parent. If the EFC using that parent’s income and assets is $0, he’ll qualify for a Pell grant of ~$6k. He’ll be able to take a $5500 student loan, and he might get some extra need based money from the school.
Look for affordable schools. Probably your state schools are going to be the most economical, and if there is one he can commute to the Pell and loan might be enough for tuition.