This one aspect to me is important because as a buy and hold investor I want to make sure that I have a good supply of possible tenants and I don't want to have to fight to get them.  

Water supply can generally be tested with compressed air so that leaking water does  not cause any damage.

There are probably breaks in supply lines.  

When I conjure up my plan but feel like there are more opportunities up north with the excess of supply.  

Being able to understand at least at a fundamental level the underlying reasons as to why the market is heading in the direction that they are as well as what is driving your specific market/area and also the principles of supply and demand is essential in the due diligence process when selecting an area to invest in. (2) Psychology- Real estate is a people business!

Tile supply company does not have our selected tile, so we will need to make new selections to keep up with our schedule.

It also says nothing about supply and demand of rental units in a given location, which would affect vacancy rates.

We've rarely gotten any pushback on our selection.The other thing to keep in mind is that someone at your lender has to 'sell' your loan request to their higher ups to get your loan approved so the sooner you supply the answers to the requests for information the closer you will be to a term sheet... or a request for yet more information.Good hunting-

Around here, there is a pretty good supply of them, with the retail for one in good shape being $5 - $6 k. 

Buy it at a pet supply or farm supply store.