We currently accept both ACH payments as well as credit cards.

(The online portal transfers money to a bank they designate to receive the ACH funds). 

I use Quickbooks for my bookkeeping and that allows payment via ACH through them.

Execicse some financial muscle and Pay off the student loan in three months.  

Someone correct me if I'm wrong, but you should be able to setup an ACH with them so they can only deposit funds, kind of like a tenant can't just withdraw funds from you only send, and then you could write and mail them a check.

Unfortunately, these cards do not permit ACH debit transactions which require both bank account and routing numbers.

However, I'd like to flex my creative financing muscle and save a good chunk of my own cash if possible.

When you define the expectation to a creative then you are assuming permission to say “this does not work”  when you have a stager that is going to get photos for marketing out of the deal they will stretch their  creative muscle sometimes accidentally not working in the best interest. 

I also have a couple that set up ACH transfers with their bank.At the end of the day you want the rent into your bank account, so why not cut out all the middlemen that want a fee?

Off the top of my head I am thinking:Me (the brains) : 40%,Contractor (the muscle): 20% (since he will be paid throughout the construction phase, and then 20% of profits after home sold)Rich Friend(The Cash): 40% since he will be providing all the money for the deal)