As I'm sure you can guess, there are many brands and types of carving tools out there. I have two little bits of advice.
1. Find a local woodworking club, look at the work from some of their carvers. Ask the ones that make items you like and would like to style your carving after, what brand tools they use. Hopefully there will be more than one. Go the your local wood tool supplier and get the heft of them,if possible try them out and buy the ones that are comfortable for you to use.
2. Quality is important to a point, but what good is it if I tell you that "Sorby" is tha best out there, you spend a fortune for a set and find out that they don't fit you hand in a way that is comfortable? None, you won't use them.
Didn't really directly answer your question, but I still hope it helps.
"Just one OLD man's opinion." :wink: