You'll experience that using the wrong measurement system will be frustrating at best.
The issue isn't you. It's everyone else. Most US-based outfits run US measure, as does Canada, at least for diving. You show a divemaster your gauge with bar as measurement and they'll look at it like a pig looks at a washing machine.
Outside North America, it's all metric, and they have even less exposure to the US measure.
I run PSI analog gauges, and set my dive computer to the local measure, and show whomever I am diving with that.