'71 429 cobra jet tear down

I have the original #'s matching 429 ci engine out of my '71 J Code mustang convertible and will now be looking to upgrade as necessary. I would like to get the compression ratio down some to run pump gas, moving forward. I have heard 9.5/10-1 is what I need to achieve to run premium pump gas. The engine will be rebuilt as stock as possible, save for the new pistons and cam required. I don't believe the bottom end has been rebuilt previously based on my intial exterior review, still has its original timing chain when I took the cover off yesterday. My question involves what pistons are required (and readily available on todays market) and what cam shaft (valve train assembly packagae) should I be looking at to replace the original factory units? I have not tore down the bottom end yet, suspect it will need to be bored after 40 + years? What would some here do to return this engine to near stock condition? It will run the original factory 14X 7" wheels, quadrajet carb, factory single point dual diaphram distributor, C-6 automatic with a 9" rear 3:25 trac-lok? I believe the factory stall converter is around 2800, can't think of what else you need to pick out the right components for the engine build. The car will be rarely driven, street and shows basically. Thanks

I know you want to stay stock as my as possible I have a 429scj that I just freshened up that I rebuild in 84 it only has 20k on the motor so I left the rotating Assembly alone witch had .030 over TRW flat tops witch left my CR higher than I wanted but Scotty J was able to grind me a cam and a distributor along with supplying a 2800 stall converter my tune is spot on so it runs like a Cheetah On cocaine using 93 octane with no pinging or knocking or pre detonation not sure what he did to deal with higher CR something along lines of bleeding off pressure you would have to ask him all I know is it works aesome and at 429 CI the higher CR you get away with the more power you have mind you that's with a good tune on the motor PS I do have dura spark ignition