My question is should I convert the previous 3 401ks to self directed IRA or just transfer them to my new employer and eventually just borrow 401k from them? 

At age 32, I have over $400K of investments with zero debt, but have yet not invested in anything outside of a Roth TSP, Roth IRA, and mutual funds. 

@Chris StrattonYes, it is possible to finance a purchase of an investment property in your SD IRA LLC.

From real estate sales, wholesaling, flipping, rentals, lending, self-directed IRA and Solo 401k investing, or tax and legal guidance, you will find that many members here are very knowledgeable in their respective fields.

This site is great if you are looking to invest into real estate, wholesaling, flipping, rentals, lending, self-directed IRA and Solo 401k investing, crypto, or tax and legal guidance.

From real estate sales, wholesaling, flipping, rentals, lending, self-directed IRA and Solo 401k investing, or tax and legal guidance, you will find that many members here are very knowledgeable in their respective fields.

You can build a portfolio with the deferred profits generated by deals done within that structure.You could purchase with the self directed IRA and then rent the space to your construction business.   

If I’m doing a BRRRR on a property, I likely won’t have many cap-expenditures come up for the first several years, as most of the house will be new.My question is, would anybody you consider putting your cap ex allowance in a ROTH IRA and letting it gain some tax free interest while it sits?

From real estate sales, wholesaling, flipping, rentals, lending, self-directed IRA and Solo 401k investing, or tax and legal guidance, you will find that many members here are very knowledgeable in their respective fields.

I was also thinking about a Roth IRA but I know that taking money out of an IRA is very difficult.