My wife and I are looking to purchase a primary residence and don't qualify for a traditional mortgage because we are FT real estate investors (and therefore are self-employed).

Red flags- low credit scores even with great incomes, eviction, roommates, not steady employment, etcWhile this is nothing other than my thought that of an experienced albeit  jaded landlord.

First and foremost, you need to convert or build a property that creates ongoing employment opportunities.  

I have never been a fan of the 401k route personally, other than I receive some employer matching.

A major employer just finished a nine figure construction project about five miles away, a new Super Wal-Mart just went up about a mile away, and a Chevy dealer just built a new dealership in town. 

That means someone on a fixed income, child support, etc. can't be turned down simply because they're not employed. 

I employ this tactic often.

I've been doing a little at a time as I can afford to  (Countertops were actually installed today.) and I planned on living there indefinitely.But, a couple weeks ago I landed a new job with a different employer that pays much better.

Figure out what area of RE you want to be in and seek employment there.

I am self-employed and won't qualify for a normal bank loan.