So many people misuse terms and quote things that are flat out untrue. A CONVENTIONAL loan is simply any loan that is not government insured. FHA, VA and USDA loans are non-conventional because they are government insured. FHA loans require 3.5% down payment with credit scores of 580 or above and 10% down with credit scores from 500 - 579. FHA mortgages do not have PMI, they have MIP which is usually more than the PMI for a conventional, conforming loan and an additional Up Front MIP that is usually financed into the loan balance. CONVENTIONAL loans DO NOT require 20% down as keeps being reported. A conventional loan can require as little as 3% down (Home Path). You can get non-HomePath financing on other properties with 5% down.
The confusion comes in with the terms CONVENTIONAL and CONFORMING. CONFORMING loans conform to Fannie MAe and Freddie Mac guidelines.
FHA loans are non-conventional, conforming loans.
Most non FHA mortgages are conventional, conforming loans.
A Jumbo loan through a portfolio lender would be a conventional non-conforming loan.
A 5/1 interest only ARM is a conventional non-conforming loan.
A VOE is not your w-2s and 1099s it's what is ordered from your employer to verify what is on the W-2s and /or 1099s, it's usually Fannie Mae form 1005. There were programs in the past that just required a VOE in lieu of other income and employment requirements but this can be riddled with fraud and these programs (hopefully) have dried up. If there are still any out there I would avoid them.
To get accurate mortgage information, always consult a licensed loan originator.