I'm currently looking to find someone to replace him, or at least supplement him.

Some recent alternatives we’ve used to supplement real estate investing include: Turo.com, and neighbor.com.We used neighbor.com to rent out the extra land for people to store things on until we develop the rest.

Any multis w/ 2 or less units, you usually have to supplement your living costs.

Hard money is to supplement the shortfall between what the bank will lend and the cash you are able to bring to closing. 

You may be able to supplement W-2'd income with draws from your investment account (assuming that's where your $400k in assets resides).

From there, a fixer-upper house-hack or live in flip might be a great opportunity to develop some practical skills that can help you supplement your income or add a lot of value economically to your purchase! 

Perhaps one of your parents is willing to be a non-occupying co-borrower on the loan to help supplement your lack of income?

Is there a particular reason why you don't want to get licensed/bonded as a General Contractor to supplement funding for your own flips/BRRRRs? 

Take half of the profit we make from the sale and invest in an income property to provide cash flow to supplement our salaries for our next purchase4.

Conventional with or without hard as a supplement will depend on your cash position compared to the deals you find.