You are good to go. You can download the rulebook from IDPA.com. The relevant portion for your question regarding guns in SSP is below:
PERMITTED Modifications (Inclusive list):
1. Sights may be changed to another conventional notch and
post type (see “sights” in glossary for further information).
2. Grips may be changed to another style or material that is
similar to factory configuration (no weighted grips; see
“weighted grips” in glossary for further details).
3. A slip-on grip sock and/or skateboard tape may be used. 4. Internal action work may be used to enhance trigger pull as
long as safety is maintained (no visible external modifications
allowed). 5. Reliability work may be done to enhance feeding and
ejection.
6. Internal accuracy may be worked to include replacement of
barrel with one of factory configuration and original caliber.
7. Plastic plugs may be used to fill the opening behind the
magazine well.
8. Custom finishes may be applied.
I can't add much more to what sbcman already posted. Any club worth its salt will welcome a new shooter no matter what type of gun he currently has, as long as it meets the caliber guidelines and is safe to operate. Saddle up and hit the next IDPA match that you can find, my only regret in shooting my first IDPA match was that I didn't find out about it sooner than I did! Keep us posted on when/where you shoot and how you did.
Ditto what Dusty Dawg said. I was welcomed in having shot another discipline not that long ago, and am now a certified SO. The name of the game is rounds down range !