You need to play the market cycles here. 

Berman How to Play the New Real Estate Syndication Game by Richard R.

I'd rather have it invested in 4-6 properties in different geographic locations (not all affected by the same market factors) that will get me a return in 4-5 months... rather than ALL of it invested in one place that will get me a return in maybe 6-12 months... even if the yield may be a bit higher... but that's not how everyone likes to play the real estate game... that's just me.

Sounds like you've heard the answer, that YES, this is a sustainable business, but I'd add that you have to play the long game in real estate.

Ask the seller to refinance the property with a one time assumption agreement with the lender - assume the loan - seller gets his cash and you get a nothing down deal.Hard money is OK (but dangerous and expensive) and so is creative financing - you'll know what is best, every deal is different - now go play the real estate game and have fund while learning and profiting - always make full disclosures and don't be greedy ---!

I used to play the 20/20 game.

I'm in Los Angeles County, CA and am interested in learning how to play the Cash Flow Board Game. 

His coach didn't teach him how to play the game, he taught Michael how to be Michael Jordan. 

Few more thoughts -  could you not play the refi or HELOC game on your primary residence (I understand you're thinking about yours and the children's future, but the present is just as important) and save for the down payment for the investment property and play refi/HELOC on the investment property.

You only lose if you quit the game....just like life.You also can not lose if you don't play the game.