Hello,

Plenty of problems come from hourly rates, the relationship is adversarial from the beginning.

Define the scope of work with the client and provide a time frame and price. File type shouldn't matter, you have to model it one way or another.

When the clients gets a deliverable and you get paid appropriately everyone is happy. If the client wants to endlessly iterate charge for iteration. It doesn't sound like the client wants to do that initially if they are bringing prints and specs, leave that as an opportunity for v2.