Planning to fail?
Attributing locations to this type of data is fairly routine in the area I used to work. Almost address validation software should get you most of the way, the postal address file the rest. (And there are plenty of companies that will do the job for you at a reasonable price - you might also get the advice you appear to need on storing spatial co-ordinates.)
But your project depends on this, and you should have addressed it early as an obvious risk.
But, as you note, there are other significant risks to your plan - depending on an unreleased product arriving on time and behaving as you expect. As others have noted, there are other products that exist now. (Even if they don't do everything, you can deliverer something.)
Simply allowing extra time is not usually a good risk management strategy. At best there is an opportunity cost of not delivering early, at worst a competitor takes the market while you are waiting.