Canebrake Jake

I am a relatively new shooter making due with available mismatched leather for now. Before buying a final rig, I am a little confused on what is allowed. I would shoot in basic cowboy class or 49er. The only holster restriction that I see in the handbook is that a buscadero rig is not allowed in classic cowboy. Would it be appropriate for me or do I need to go with the double straight or straight/cross combo?