There are a plethora of clarinet mouthpieces, reeds, and ligatures being made nowadays, and as many musicians who swear by their particular "setup."
Some sponsored professionals give props to their setup (instrument, custom barrels or bells, mouthpiece, reeds, ligature) at the end of their biographies in concert programs. By no means should one ever, after enjoying a great performance by a clarinetist, run out and buy whatever they were playing on.
You won't magically sound like them. It's not how it works. In fact, many clarinetists change their setup several times over the course of their careers, and often alter the reed/ligature combination depending on the venue they are playing.
Confusion over the best "setup" to play on increases with the ability to afford various mouthpieces other custom clarinet parts. When you can afford to have (or afford to buy for your child) the best, the search for "the best" can become, frankly, stressful.
I am not going to make any specific endorsements here for particular brands or models or makers.
What I do recommend is that you keep in mind the Objective from the Subjective.
Objectively, there are 4 necessities for a mouthpiece/reed/ligature setup:
2. Core of tone color
3. Ease of articulation/response
4. Ability to maintain the above three at various dynamic levels
Subjectively, there are a number of considerations. To name just one, some players prefer mouthpieces that have great flexibility in tone color, while others would perceive the same properties as too unstable.
The most important thing to keep in mind when considering changing your playing setup is to change only one thing at a time, and to not change anything very close to a concert or audition.
It is also imperative that one always have other people with good ears hear the setup and help you make a good decision. A common error in picking equipment out on one's own is choosing a mouthpiece that seems brilliant and full, but upon longer trial, the mouthpiece plays horribly out of tune or has some other fatal flaw.
Finally, especially at the student/amateur level, there is no magical setup that will make you first chair.
Whatever your budget, wherever you are, you are the one who must make it work.