Lender refinancing question and advice

[Ian K.]

Hello

I'm in the process of closing on an investment property that I ultimately want to use as my primary.  We have to purchase it as an investment because their is a lease in place for the next 9 months.  The sellers appear to just want out so there is a considerable discount.  In 9 months I intend to move my family into the home and then do a refinance cash out at the primary occupancy rate.  I'm interested to see what I need to consider on the refi side-length of time occupying, proof of residence etc.  

A potential other wrench is that I had to take a HELOC out on another investment property to for the down payment on this investment purchase. When I refi I want to pay off the HELOC but not close it out. I'm afraid that losing the rental income on the property and now having the mortgage count 100% as debt and the HELOC debt will prevent me from getting the refi due to DTI unless I close the HELOC first?

Thanks for your time,