Unfortunately, no, as I've changed country of living year ago and still can not find way to good tea in new place. Also, I'm not sure, that recommendations from Europe is actual for you even if I have one.

But really best "black" tea of my life (and I spent most of my life in country with strong tea culture, where loose tea and teapots are still very popular, and not, it is not UK!) was bough at random tea factory in the middle of nowhere in Sri Lanka, packed in simple 1kg vacuum bags. No brand, no name, only date of picking (two days ago) and packing (today at the day of bought) :-)

As a local, the brand called Dilmah is just a regular supermarket brand for us, but I hear it's quite popular in places like Australia and New Zealand.

Ahmad Ceylon Tea is a good strong black tea. They mainly trade in Middle Eastern markets I think so check Arab/Indian grocery shops