Right now, your retirement plan most likely has minimal choices to invest in (some stock funds, bonds, ETFs if you are lucky) so you are rather limited in choosing an investment vehicle that will help you reach your goals.From first hand experience, I can tell you that getting a solo 401k was rather easy and I have checks that I write to pay for properties free and clear or to put a down payment if I want to get a loan.

We plan to continue educating ourself while overseas and practice analyzing deals from a distance.2) there is also all this talk about the market (stock/real estate) correcting late 2019/2020.

@David Smit"Where imposture, ignorance, and brutal cupidity, are the stock in trade of a small body of men, and one is described by these characteristics, all his fellows will recognise something belonging to themselves, and each will have a misgiving that the portrait is his own."

A lot of variables for anyone to be able to accurately predict the future of housing market (or stock market).

My understanding is that there that there are three rungs:1) "Garbage" companies think penny stocks - poor return/risk profile2) 500k-1.5m companies (20-30% a year???)

There are several ways of doing this without incurring taxes or leaving your money to the whims of the stock market.

Both stocks and RE are good investments over the long term. 

The stock market never shows that there a negate times and it is looked at very well because of it's complication of the Stock Market and contributions are higher versus Real Estate which only might have more to learn but is easier to learn the basics. 

Contact 2 or 3 to interview them personally then make your choice.TD Ameritrade and Fidelity do not offer truly "self-directed" IRA, they might offer some control, but only within confines of their allowed investments, which is confined to the stock market and does not include alternative investments such as private lending. 

I think of it a lot like retirement funds - start aggressively with value/growth stocks and ETFs when you're young and have time to play with, move into highly rated bonds and low-fee dividend funds as you get closer to retirement.