Do you service NJ?

ARV's you'll need to team up with someone who has access to MLS in the market or try a service such as Propelio that will give you access to COMPS.

Is there a one-stop-shop kind of service for this? 

Schedule C on your taxes is titled "profit & loss for business" so with your STR income now being labeled as a business, (because it is) lenders will want to see consistency and growth in order to be able to use any of the income to offset the STR's debt services.  

I have been talking with my mother who has been working civil service for the government for over 20 years.

The first time I wrote a dissertation https://www.prospects.ac.uk/applying-for-university/university-life/how-to-write-a-dissertation, it took me a full week (and 2 more days for final editing and proofreading) to fin...

Ask, "Is that the best you can do on price (or terms or whatever you are trying to achieve)?"

That meant going from 100 amp service to 400 amp service from the street, and replacing all the boxes in the basement from fuse boxes to circuit breakers.

So i would typically add an extra line after debt service to account for CAPEX without affecting my NOI. 

I am also all for asking for advice and review from people who have achieved what you want to achieve.