You can also shim your 25.4/26.0 mm bar to a 31.8mm stem with suitable adapter. You can get them in silver or black finish:
https://www.amazon.com/Wheels-Manufa.../dp/B000AO5FME
I find these tools indispensable in making stem / posture change decisions:
Stem Comparison Tool | yojimg.net
Stack and reach calculator <-- more work but great for comparing different geometry bikes, provided you have adequate manufacturer's geometry specification to plug into calculation
I have used these inexpensive Dimension (QBP) stems, they are offered in a wide variety of sizes, black or silver, at relatively low cost. Better quality than you would expect for the price:
https://www.dimensionbikeproducts.com/products/stems