I don't think you need to go so fancy for the work you want to do. You'll be using softer leather which is turnable and "round dent" irons are what are generally used. I suggest Wuta irons. They're inexpensive, sharp, and the teeth are replaceable. The smaller the size, the tighter the seam.
https://www.amazon.com/WUTA-Removable-Stitching-Professional-Generation/dp/B0B4C35HWD/ref=sr_1_2?crid=2NZ629BROW6HC&keywords=wuta%2Bstitching%2Bchisel&qid=1703644653&sprefix=wuta%2B%2Caps%2C101&sr=8-2&th=1