Welcome Mike!
I too have a body shop and just can't afford to buy tools and equipment on a whim so I build almost everything. With a busy shop though, they tend to get built on a as-needed basis.
I learned early on when I made the transition from collision work to muscle car restoration that most of the patch panels out there are junk. I soon found it much easier to make a patch than buy one. I'm still at the mercy of the stampers when it comes to quarter panels though... No way I am going to be forming a 6' to 8' long panel anytime soon
The 2 events a year out of all the shows I attend that really get me going with metal shaping is my local Metal Meet. I'm sure someone in your area will chime in on when and where your local one is!