Welcome to the forum! Leather tools are just like any other tools; you can buy cheap or you can buy top of the line. For some non-leather projects, I buy tools from harbor freight. For others, Craftsman (when they were decent). Same with leatherworking tools for me. To me, a edge slicker is an edge slicker. I started out with a cheap tandy swivel knife, but have since upgraded to a Barry King. I started out with Tandy edge bevelers and even tried some from Amazon, but ended up buying a set from Weaver Leather. They work great. Same with stitching forks. Some folks say just buy the best up front and save yourself the trouble of having multiple buys. I have done this too and end up with a pricey tool that I don't use very often. Starting out, I wasn't sure if it would be something I stuck with long term. I have been playing around with leather for 3 years now. Still a hobby. But I have noticed, with better tools, the craftsmanship and quality are much better. The sad part is, I know folks who could make beautiful items with the same cheap tools where I couldn't.
Some common names of good tools are:
Weaver Leather
Barry King
John James Needles - several articles on here for that including thread to use as well.
Makers Leather Supply - for templates, patterns, etc.