There is no seasoning requirement involved since the property isn't a short sale and it isn't someone buying REO from a bank with a seasoning requirement.

I’ve done some research and have found that some banks will allow the seller finance portion from the seller to go towards the down payment of the loan, is that true?

Make sure you know where the guard rails are with your bank. 

At this point, I would recommend having a line of credit to cover these things so you don't have money sitting in the bank doing nothing when it could be put to work.I have 33 units, no debt except for mortgages, and excellent income.

Quote from @Brandon Croucier: 12 or 24 Month Bank Statement is probably the best bet.Where would I get one of those? 

I am primarily hosting traveling medical personnel because there is a lot of demand for these professionals in our area and because my units are suited to their needs.

Of course the OP received the funds but the point I would argue is that if the OP received in Jan and not Dec in his bank account.

For bookkeeping purposes, I recommend designating a separate bank account exclusive to the house hack activities to keep some sanity.

I bout one in 2019 and it has turned into a gem for me, but at the time, it would not have been 1.25 1.25x is a very common DSCR for a bank.

We are not too strapped for cash, but it always seems better to have more in the bank than less.