my condolences on your recent lost.there are a few ways you can do this, as mentioned above you can take a heloc on your primary residence which will give you a second mortgage, first mortgage payment wont be impacted. you can do cash out refinance which will give you one mortgage and payment. it will pay the old mortgage and give you money in your pocket to pay for the rehab.or you can do a renovation refinance which is similar to cash out refinance but we would contractor involved  as part of the refinancing and they are paid through the loan

Use some for a down payment on your next home.

i can send you a few i use and trust. send me a message to share

If there are no other red flags on the tenancy (i.e payment issues, lease defaults) I would still renew tenants (even if they are a little corky!) 

I honestly wouldn't trust anyone else with my clients but him when it comes to that local market.

As others have suggested, you could get a conventional or FHA loan if you want lower down payment options.

I consider the two best sources is from other trusted contractors and other RE investors.  

Prepare financially by saving for down payments, improving your credit score, and setting aside emergency reserves.

He may know some GCs so I'll reach out- but meantime if you need an inspector you can trust for before, during or after construction, he's a Godsend. 

It’s also helpful to build a small network of trusted vendors and tradespeople you can rely on for future projects.The BRRRR strategy can be a great way to scale, but I’d advise budgeting some extra cushion for unexpected costs or delays—it’s almost inevitable.