I've gotten chinese clone keycaps from Amazon, they're fine as long as you get like doubleshot and read reviews.
If you've got the money to spare or find a deal (like myself and a friend split a buy 1 get 1 free deal) check out Drop.com. A decent selection of high quality keycaps and imo are such a comfortable profile (MT3) but if you prefer a more conventional cherry profile, they carry those as well.
My daily driver at home has Drop X Noctua MT3 keycaps from drop and my work keyboard currently has some XDA Botanical clones from Amazon. Both are good, the Drop keys are better though.