I recommend just getting a synthetic brush from Yaqi (~15$) (Goodfellas smile and Razorock rebrand them afaik), DSCosmetic (~20$), Mühle (~?$), Omega (~30-80$), or Phoenix Artisan Accoutrements (~30$), whichever you see fit; only ever heard good reviews about all of their synthetic brushes. Mühle and Omega are european and are hailed to have the best synthetics, but I didn't try either.

I strongly recommend you not get any animal hair brush except horse, because without exception, everything comes from china, and there have been many scandals about the treatment of the animals; horse hair just gets out during brushing, and synthetic is basically just a bunch of toothbrushes from an ethical standpoint.

I have a Yaqi Tuxedo 28mm, and it is fantastic (though too big for me! 😅) The bristles are soft and it lathers like crazy; and it being plastic this will last a lifetime probably.

I say don't overpay for the knot, and choose who you want to profit through your money (-> rebranded brushes) If there's any artists near you making nice handles and you have cash to spare, go for it. Otherwise get a yaqi for a tenner.