I don't have a specific recommendation, but suggest you don't try to combine the paper and digital requirements.
Look for UL fire endurance ratings. UL rates them on time and temperature. Edit: I've seen ratings up to 3 hours, but the longer the time, the bulkier and heavier for the same storage volume.
For paper, you'd want something rated to stay below 350 degrees for at least an hour. That's not hard to find even in large sizes. I ended up with a used FireKing 4 drawer file cabinet from a company liquidation sale. Edit: Built like a tank, holds a lot, uses a Medeco key, weighs a couple hundred pounds empty.
For digital, you need something rated to stay below 125 degrees. That's pretty hard to find, and usually only in very small boxes. Unfortunately, some companies (looking at you, Sentry) like to advertise "digital media" boxes which are not rated for 125 when you read the fine print. Not sure how they get away with that. :(
I eventually found a small Sentry chest rated for 125 degrees for 30 minutes. Holds a couple hard drives and some DVDs. Sadly, do not recall the model number. Edit: Storage volume is maybe 5"x5"x8", walls are all 3-4" thick.