A few additional thoughts from an RV-10 builder who is getting close to ready to move my project from the shop to the airport for final assembly and first flight:
While I make extensive use of the air drill, I also find having a cordless drill handy with a straight flute reamer to slightly open the occasional rivet hole when driving rivets and the rivet won't fit is worth having. It's also useful for things like step drills with 3/8" shanks that won't fit in the 1/4" air drill.
Instead of the C-Frame, I strongly recommend you consider a DRDT dimpling tool. It provides much more uniform results, and is much quieter.
I found having a pneumatic squeezer to be very useful. Yes, I could have built with just a Cleaveland Main Squeeze, but the pneumatic squeezer was my go-to tool.
Get at least one good Tungsten Bucking Bar similar to the Cleaveland BBT41. It's expensive, but it was the bar I used for probably 95%+ of my driven rivets.
Since you are a first time builder, I would recommend you spend the money to take an introductory EAA sheet metal class. This class helped me get quickly up speed and to make my mistakes on the practice project instead of the empennage.
I also took the Synergy Air empennage class. This class was a great way to get quickly started with my build, while having the opportunity to try a wide variety of tools and techniques which helped me decide the tools I wanted to buy for my project. If you can afford the time and cost, I would highly recommend you consider this. For me it was well worth the investment in this class, as I avoided many newbie mistakes and I believe have a much better quality aircraft build as a result. While your having a local A&P for help and advice is good, unless the A&P has built kit planes, he will not have the skills and experience the Synergy Air A&Ps have to impart to their students.
Welcome to the aircraft builders world. Hope you enjoy the journey.
RV-10 Finishing Kit & FWF in-progress
2018 VAF Dues Paid