In the vaguely unlikely case that the cap rate and deal is real and there aren't any significant "gotchas," 25% down should be easily doable.

What is your current mortgage rate? 

@Bill Brandt could you share how much you charge for, pet included deposit and any one-time pet fee ?

Its a fee for tax planning and financial advise. 

The terms of your mortgage and interest rate will remain the same and no refinancing would be required.

It is going to be a VARIABLE rate and is typically higher than a cash out refinance. 

I want to do things the right way, but feel the pressure of a tight budget that will get drained considerably by the permit fee and multiple inspection fees. 

It's certainly much harder now to cash flow while house hacking with high mortgage rates, but not impossible.

There are other loan products out there with a varying degree of rates that could be alternatives, but I'm not an expert in mortgage products so I'd recommend speaking with a lender first. 

Short term rentals usually price best 65-70% loan to value but if the cash flow is very strong to support a higher rate up to 80% is still possible these days (not common though).Best of luck.