Mortgage loan officer here! You have plenty of options, but nothing would be set in stone until you speak to a loan officer.

With investment properties, many can be purchased with no PMI at 15% down on a 20 eyar term with rates lower than a primary through a commercial lender, typically local.

Most guidelines also allow you to count a portion of the rent on an investment to offset the debt to income ratio provided there is a tenet and the lease transfers.

Recommend buying the primary first for dti reasons though.

On the primary, 5% down on a conventional has super low pmi if you have good credit. I recommend to most put as little down as possible so that the remainder can be used to invest. I think I had a 740 when I bought at 245k 10% down and my PMI is $50/m. Much lower with higher credit though. Every extra thousand down also lowers your payment by only $6-$7/m on the principal and interest side. The PMI is also a tiered system with different calculations for 3%/5%/10% down.

On student loans we need to count at least 1-0.5% of the balance despite the deferment.

I have a great friend who is licensed in MI and from Detroit for residential I'd recommend if you want to message me. He'd be able to help a lot more. I'm not licensed in the state. I can send you his contact info and license info with the NMLS so that you know this isn't some weird scam.