If not eligible to set up a Solo 401k and you have funds retirement funds which are eligible to rollover (e.g. funds not in a current employer plan), you can rollover retirement funds to an IRA at an IRA provider which allows for alternative investments. 

I tried looking into alternatives like self-directed IRA's to avoid the penalty & taxes but it's extremely restricted, and it seems that the only purpose is to make money for the IRA.

I seriously doubt that , there is a whole lot more being a contractor than truck tools and insurance .

The other alternative would be an over-funded permanent life insurance policy.

It’s an alternative to a loan.

Alternatively, you could buy cash and then get a private lender to loan you money in exchange for a 1st lien position (ie be the bank).

Can’t say I’m surprised, but what are their alternatives?

Like what's better a truck or SUV?

Alternatively, If your numbers are accurate, there is definitely enough spread to work with a HML if you are employed, have decent credit and can put some skin in the game (ie 10% of the purchase or so).

I would have hooked a chain up to that rickety piece of junk to my truck and drug it down the street with the idiots still in it before people would be setting up shop by my property like that