Shavano Park is a great place to live and own a home. My recommendation is to build. So many homes for sale confirms that it is a buyers market. Seller's are more negotiable now. Interest rates are still low, but trending up. I say build now while prices are slightly depressed and before interest rates move up.
It depends on your wants in the home and your long-term plan.
Wants: what is it you must have in your new home? Will a pre-owned meet your requirements?
Plan: what is your forecast for the length of time you plan to stay in the home? Under 5 years may mean buy and remodel. Longer than 5 years means possible new construction and when you may be ready to move, the housing market has improved.
Your questions is a little thin on many of the particulars. Suggest you find a real estate agent you feel confortable with and start asking questions to help you really get a firm vision of what you want/need.
Chairtian Realty San Antonio