since you don't have any legal structure and don't want to waste time and money finagling with lawyers etc, I suggest you borrow the money at a reasonable rate of interest (say 7-8%), and defer interest and repayment (set yourself a generous repayment schedule) beginning on a date, let's say 2 months after launch, for when it converts to equity or repayment begins.

This way you have cash in hand now, and details can be worked out as the product matures. If the house burns down you probably ending up owing maybe a $1000-2000 over the initial $25K, totally worth it for the freedom IMHO.