Could you put it on a CC and pay it off within the billing cycle with either your income or selling some stock if absolutely necessary?

CA has the highest income tax rate in the county.

Here are a few strategies to consider for funding a down payment:Partnering: Like Gregory mentioned, finding a partner who can contribute to the down payment in exchange for equity or a profit share is a solid option.HELOC or Cash-Out Refi: If you have equity in your home or another property, a home equity line of credit (HELOC) or cash-out refinance can provide the funds you need.Private Money: Reach out to friends, family, or private investors who may be interested in lending you the down payment with a promissory note.Seller Second: In some cases, the seller might agree to finance a portion of the down payment as a second mortgage.Live Frugally and Save: It takes time, but reducing expenses and setting aside funds from your income is a tried-and-true method.The right approach depends on your situation and deal structure, but a mix of creativity and resourcefulness can go a long way.

Not a lot of our competitors offer this but it's something we can consider (but for us, it can't be in a rural area, the loan amount must exceed $150k, if we're using PadSplit income (or STR/MTR income) the max LTV is 75% and the down payment must come from your own funds). 

I needed to find a passive real estate income stream that would work within the IRS’ self-directed IRA (SDIRA) rules.

Too many low income apartment buildings near by / vacant buildings. 

At this point, I would recommend having a line of credit to cover these things so you don't have money sitting in the bank doing nothing when it could be put to work.I have 33 units, no debt except for mortgages, and excellent income.

Additionally, Airbnb income during this period could generate steady cash flow, though market conditions and regulatory risks should be considered.

However, with a SFH you will lower your standards when vacancy arises more than one month as you have no income coming in to male that payment.  

If your goal is passive income, it's not going to be in New Jersey when you factor in cost to purchase, management costs, and rent to price ratio, but what you can get is steady appreciation.