6 months' worth of mortgage payments saved up to be approved?

[David Ingram]

Hi all! I have listened to BP Podcasts, read about 4 books from Brandon Turner and I'm getting my ducks in a row before I pull the trigger and finance my first long term rental. Talking with a lender I may want to go with he advised me that for a conventional loan, or any loan for that matter that it would be a good idea for the underwriters to see that I have 6 months worth of mortgage payments saved up in-order to be approved for a loan. It doesn't have to be liquid, it can be IRA, 401K etc and that will work. I am W-2 and I pay full mortgage for my regular live in house. There is NO way I could have 6 months' worth of mortgage saved up to finance another house.

FIrst, is this true what I am being told? 

Is it true even if I have a private or hard money lender to finance my down payment?

Any work around?, should I wholesale to stack my bank account before trying to get financed for a loan?

Thank you all for your time.