Just to let you know our experience. A year or two ago, we had some paperwork, that they would not accept (we only extended our lease for 6 months, as we were planning on moving, and apparently, they wanted a year). Anyway, because of this, they extended my visa temporarily for 1 month, while we sorted everything out. So, while I think you should be fine, some peace of mind is that they often will work with you, to help you, if you don't have all your ducks in a row, and are not looking to kick you out of the country.

For us, the two people we used as our witnesses, were the home owner of the house we were renting, and his wife.