I don't want to refinance because my current rate is under 5% and doing so ruins the cash flow I've got right now.

I'm making a healthy downpayment cash by doing a cash out refinance on three of my established properties that I know can cover the debt service handily.

Quote from @Daniel Tanasa: Another option is to get a small cash out refinance from the house you plan on fixing up, if is in financeable condition, and use that to fix it up, while still cash flowing.

I’m considering doing a cash-out refinance, not sure what the best options is , to use the rental property or the rehab property.

I can help with the refinance to pull equity out, but no the purchase, as 99% of the industry won't finance mobile homes. 

If you are borrowing $150k, rates will not likely drop enough for you to justify a refinance due to lower rates.

You can refinance into a FHA 203k or like @Jason Wray mentioned you could even use a Fannie May homestyle renovation loan as well!  

@Robin Simon I completed a refinance with my credit union at terms of 3/30/75 @6.85% I will have the renwal in 2026 and hoping rates come down a little by then.

Then once you've fixed the property up and at least have it listed for rent you could refinance into a DSCR loan.

You get money at closing and then you refinance when rates go down.Anyone done this before?