Ok, now we are accurate, because that truly is all that buying all-cash does.

Too little information to give an accurate answer.  

I have been looking for the best system to get the most accurate results with the fewest possible steps.

@Ash BisariaRecommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

Do you have a system you do when budgeting to make sure you are accurate with your numbers? 

If the software is not simplifying your life or making you more accurate, you shouldn't use it.

It's just about having the right team in place where you can identify them and get offers submitted quickly and solid contractors that can give you realistic quotes so your financial forecasts are accurate. 

This is powerful, assuming I assess the rehab costs accurately. 

@Johnery LaurimoreRecommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder, etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

For rental properties in general maybe looking at (debt+proposed PITI)/(wages+(75%*rent-current PITI)) might be the formula that would be more accurate.