Welcome to Dallas. You live a long stone throw from me and yes it's a great area for spotting high end cars.
Your local dealership is Park Place Porsche located near Love Field. They do good work but are not shy about charging dealer prices. The parts counter at Boardwalk Porsche (Plano) typically has better pricing for those last minute repair projects. Zims Autotechnik is another option for parts but is more of a drive.
DFW has a large number of independent Porsche shops; I typically use RUF in Addison. Download the latest Slipstream publication from PCA Maverick Region to see ads for many of the popular repair and parts places.
http://mav.pca.org/Newsletter/Newsletter.asp