OkeyDoke,
For sure peening is a good way to increase the fatigue life, am not sure however that it could be really beneficial for your application ($ vs improvement).
Anyway, to answer your questions, AMS-S-13165 will not recommand peening Titanium or Steel section under 0.09" thicknesses. For aluminium, it is suggested to use an intensity of .004 to .008 N using glass bead or ceramic shot.
If you wanna approach local shotpeener you need to tell them what intensity u need and the coverage desired (100% is standard).
I think Metal improvement might have a facility in San Francisco or around and they have been doing it for a long time.
Well you might wanna be extra careful on how the part will be peen if you wanna avoid deformation. Manual and wheel machine might cause more deformation than robotic peening, but robotic peening might be too expensive. Like I said before am not sure that it would be beneficial for your application.
Just out of curiosity let me know the outcome of the test if you run some!
