Need minimum required expat health insurance (Berlin)

Hi Group. After 4 years in China, I've decided it's time for me to move back to Berlin. I lived there in Protected content . Naturally in order to get a visa, I must prove I have the minimum amount of health insurance required by DE law. I thought the company where I bought "special insurance for teachers" was called "Dr Wattson" (or something like that.) I can't seem to find that company now, however. So my question is this... Can someone recommend a good site for finding health insurance for expats?

I've checked earlier posts but see most replies are "I can help you with that..." ... What I'm looking for is a good site where I can compare insurance sources...

Many thanks!