Two of the brands Yorkshire and PG tips are honest English tea, they're what you'd be served in the U.K real honest to God tea and if you've never tried it you'll die over the amount of flavor U.S tea is stripped of.
Red rose I think is out of Canada and is an outstanding red breakfast tea, it has a bit more of a malty flavor so it carries over into iced tea crazy well.
Tetley is bordercentric like Yorkshire has become, it is good tea but U.K markets get a beefier blend than we do.
Kudos on doing the loose leaf option, if you aren't' a sufferer of the "too much touch" like me loose is great.
I end up stuffing that tea ball way past the point of ridiculousness and it ends in disaster.
I do say f'it and use it for my Gypsy coconut chai, it has whole cloves so that ball just has to suck it up and try not to die.