I use QuickBooks Online for most of my clients.

My wife and both make a high income for our area and I feel we could save about $100K per year to keep buying. 

I was by default going to set up a Florida based LLC with my partner.This is a buy and hold, rental income property.How would you go about setting up an entity out of state?  

Not to mention I got to write off over $175k from my income taxes using a cost-segregation study.  

It comes down to how one country will tax the income and then how the home country deals with it.

I am trying  to purchase a multifamily house , outside of the city where i live it wis about 150  miles from my location ,  how do i figure out the demographics of the area and also the medium income around the area where i am planning to purchase . do i need to look for any big stores/shopping malls or any govt offices around the area to see if the place would be ideal for purchasing the property for renting it .

I am able to work as a travel doc, and she works remotely in tech, and we plan to use our combined incomes to put towards REI, as well as keeping our cost of living reasonable!

Several of my recent buyers have been medical and legal professionals with high taxable income, that are looking to expand their value portfolios by incorporating an accessible short term rental property (often doubled as a legacy anchor) that will often offset or 'pay for itself,' in tax savings. 

Your greatest challenge is going to be running this management company without the appearance of co-mingling all of the LLCs together.Bear in mind that one of the things that you'll be doing here is converting Passive Income to Earned Income via the Mgmt Company and that will be subject to self employment tax whereas had you left everything in the property LLCs, you'd have only passive income. 

If you want true "Passive" income in real estate, you need to have a lot of cash to put into it.