Trivia, there is almost no true IPSC shot in the USA. For whatever reason, USPSA that started out as the US Region of IPSC has gone its own way with its own rules.
There are club locators in
www.uspsa.org and
www.idpa.com
For the sport, I recommend a Plastic M&P Pro 5" 9mm. That will get you into USPSA Production and IDPA Stock Service Pistol. It can be refined with Apex parts or gunsmithing by Burwell, Bowie, and probably others; but will be satisfactory out of the box.
I have a Burwell tuned M&P Standard which is ok but a little more sight radius wouldn't hurt.