A bit after the fact but maybe find some use of the info. 

This tool (no affiliation with BiggerPockets) can help your son find properties with assumable loans. 

If you can't find what you're looking for, try the Bigger Pockets Fileplace.

BiggerPockets has a decent system for finding a real estate broker in any given area.

Did you ever find a solution?

You can also start by being a "bird dog" and finding off market deals.

Every deal has a challenge—whether it’s a seller with an unclear title, a property with zoning issues, or just finding the right buyer who actually sees the value.I’ve been navigating all of this while working on land and mobile home deals, and honestly, the problem-solving side of it is what keeps me hooked.

Quote from @Jaheen Ahsan: Hello,So I bought my first house hack back in July, and I've been trying to find roommates for about 6 months or so and haven't quite had any luck.

Additionally, the price point is still cheap enough to find the 1% rule and positive cash flow and it's super landlord friendly.

I think @Paul Sandhu captured the list of skills you need to find, and that you can probably find someone with "3M Talent" (or at least "2M Talent" to cover several areas.)