Home loan qualification questions

[Preston Timothy]

I have decided the multi family is the best path forward for my current life situation. 

I would like to purchase a three or four Plex and live in one of the units.

I understand I can use an FHA loan or conventional loan with only 3 to 5% down in order to get into the property however I live in a very expensive area and the properties I am looking at are currently 700+.

 I only qualify for about $500,000 with my W-2 income.

Without getting a private investor, is there anyway I can prove previous rental income in order to use the potential rental income to qualify for the loan. If so, can I do this with a conventional mortgage?