@Mikhail Llauder, what's going on! Congrats on setting some goals and working towards them. The VA loan can certainly help get you there and you can build a decent portfolio while moving around. While overseas you may have a bit more of a difficult time since you get OHA not BAH and they are treated a bit differently.
The SDIRA is a great plan you just have to invest in other people’s deals for that as you can’t invest in your own deals.
As has been mentioned, make sure your financial house is in order before you start buying houses. Get out of bad debt, have money saved up, etc. then jump into buying a property. You can do turn key investments while overseas which would help you out but that means putting a tradition down payment down and not using the VA loan. Still get you going but a bit more money involved.
I would love to help however I can as that is what I focus on: helping military members and their families with real estate! Hit me up if you have any questions.