I disagree with the objective of a combination trophy room - reloading room - study; "trophy room - study" yes, but not reloading. I would encourage you to think about an oversized garage front to back, with the back walled off for a "gun room". A gun room, includes reloading, storage, cleaning & maintenance and repair etc. You are not going to have cleaning and repair in your "study - trophy room" so you'll need another place for it so why not all inclusive to start???
I have the aforementioned setup. Everything in one place, concrete floor with rubber mats placed appropriately, two benches (one for reloading and one for cleaning, maintenance, repair etc.). No issues in garage with smell, spills etc. The most important things to think about right now are not cabinets etc, but wiring, lights and plumbing (shop sink and small countertop - wish I had one...).