Bravissimo in the UK are also great for larger cup with smaller back sizes and ship to CH, just add a note asking them to wait for all the order before shipping to avoid multiple tax charges...
I find the support sufficient and I am a D cup. It's true, they are more like bustiers than bras, but more supportive than bustiers and soooo comfy, and for the sexy occasions I can still get into something underwired and lacy, but for everyday at work they are great. And it's simple you order your clothes size.
Hope they work out for you. I tried wearing a second on top of the first and that was much more support, so you can play around with them. As you said, they are good for every day and especially at work I find them so comfy.
I buy most of mine, which would fit your description, in H&M these days. They have quite a lot of really nice bras at a good price, it is worth checking out one of the bigger shops with a big selection.