There isn't a set number of houses you should see before you decide. Visit as many as it takes to find the one you want. On average, homebuyers see 15 houses before choosing one. Just be sure to communicate often with your real estate agent about everything you're looking for. It will help avoid wasting your time.
When comparing warranties, check the length of the warranty, whether or not it’s pro-rated, and if it covers the labor for replacement of a defective item.