Therefore, we will be liquidating shares of our Vanguard index funds (held in a general brokerage account) to make the down payment. 

Best way is to get a payoff on the account which i typically do during the research and consultation stage with the client. 

So the basic financials are $281,900 purchase price, $100,000 rehab cost, then when this is complete the income of the property would be $850 and no utility expenses.I am planning on using the BRRR strategy for this property.My wife and my personal finances is I have $14000 in savings, $600 in another account and I have a line of credit of $40,000 with and interest rate of 7.8%.I have not exactly officially offered this $281,900 but I want to but before that I want to hear any opinions and things I may not have thought of.

Aren't 2nd or 3rd position liens accounted for in the upset price?

Account Closed yes that is what happened.  

@Jeremy VanDelinder game a good point of reference as well with his account of, "... in Austin I was able to do that "full gut" fire house for $77.60 psf with my contractor..."

I held several jobs in the retail/wholesale apparel industry particularly in sales and account management. 

Retirement accounts are designed to be invested passively (i.e. rental property, trust deed, note fund, syndication, etc.)

You will want to setup a bank account that goes with your LLC.

Equity Trust is certainly one of the biggest and well known custodians of SD IRA accounts, but my experience with them was not great.