Technically speaking their is two paths to go down when thinking in terms of security. CCMK4(Cold Card MK 4) air-gapped hardware wallet feature(I have a tutorial for this on my YT + Rumble) or a combination of the BitBox02 BTC only and CCMK4. Pair this with Sparrow. Open Source only. To set up a btc node look at Ministry of Nodes on YouTube until we drop a tutorial lol.