Self Directed IRA investing to maximize use of my funds

[Todd E.]

My company has been purchased and the division that I am in will be sold through the divestiture. 

This will allow me to move my 401K into an SD-IRA, of which all the funds will be used to purchase SFR's, all-cash (no leverage).

About half of my 401K is Roth and the other half is pretax money. 

Looking for Pros/Cons of converting all the money to Roth prior to rolling to SD_IRA and then investing in SFRs. 

Secondly, and more importantly, I am seeking input on the best way to set up the SD_IRA to minimize overall costs. 

The best structure to maximize the use of my funds and minimize all the setup, annual, per transaction, ... fees.

All the SFRs will require rehab, so there will be several outgoing payments from the SD-IRA initially per property, and (if all goes as planned) monthly income from each property going into the SD-IRA.

I am confident that someone has already navigated these waters and hope that many of you have had a good experience doing so. 

Would appreciate your guidance and direction.