As for Cash flow, I think it depends on the deal structure as you mentioned, but also strategy/approach (cash flow vs building asset, holding long term).

You set your own payment terms with YOUR client and then find funding for them.The Capital Syndicate is a private lender firm that offers financing through their own company, but they also provide you with a list of about 150 other private lenders. 

Hard money loans can be an option, but they often come with high-interest rates and short repayment terms.

Has anybody found a workaround for this or would the seller simply have to hold the note long-term without the option of selling it?

You can force appreciation by rehabbing and such - so that might be a shorter term way to go?  

A lot of rehab lenders will account previous reno expereince when it comes to terms.

Selling for $380k means an $80k taxable gain at long-term capital gains rates (0%, 15%, or 20%, depending on income).The $80k HELOC used for personal debts doesn’t affect your taxes.A 1031 exchange could defer taxes, but you’d need to reinvest in another investment property, not a home for your mom.

I think holding is a great long term plan.

Normally the escrow agent will want mutual sign off even if its clear the contract terms indicate one party should be awarded the escrow funds.

Depending on what the potential jobs offer in terms of income, does this seem like a realistic strategy?