Guangzhou's social security is more comprehensive than Foshan's, regardless of pension and medical care. It's better in Guangzhou, but if you live in Foshan often, it's more convenient to buy social security in Foshan ~
I am affiliated with Guangzhou Huanchuang to buy social security. You can consult.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.