thank you all for answering my questions. I guess I should do a better job to explain my question.
this is a hypothetical example: I have all the accounts I mentioned above: old 401k, current 401k, Roth IRA, personal trading account. let's assume the money parked in these accounts are roughly the same. if I want to use self-directed IRA to invest in real estate, I can roll money from my old 401k and Roth IRA.
now let's assume I find two properties, one is cash flow property, the other one is appreciation bet. I like both, I want both to be in my portfolio, so I am diversified. my question is: given that I have multiple properties I want to buy, and given that I have money from multiple accounts, how do I best match the money and the properties so that I can maximize the tax benefit, as well as cash flow needs?
thru self-education, I think it's better to use SDIRA(rolled from my ROTH IRA) to buy value-add property, and buy cash flow property using my bank account(as I need to have stable cash flow that I can use on daily basis). but I don't know whether my answers are correct or not.