Don't worry about a dyno is my best advice. Yeah, it's nice to have but I am sure you can make friends with a local shop to use their dyno during off hours.
This is coming from experience and not forum hooplah. It's best to get on your feet first, have your bills and employees paid and have money to cover overhead for at least two months. Sounds like overkill, trust me, it's not.
This is not a post about dyno information which is what your thread is about, instead, it's just financial information coming from experience in what it takes to not just open, but to stay open.
Sunny days are nice but it's the rainy days is what you should worry about.