I don't think I dare look at that site!!! Nicky's Nursery is bad enough with about 200. Realseed Company much smaller but unusual varieties.
Personally, Stupice didn't do for me a few years ago. Like Lettice I try several varieties each year - some that have done well and some new ones. All are grown in unheated poly tunnel in the soil in south west Scotland. 6 degrees C in there two nights ago!
For small cherry tomatoes that are early and prolific I go for Chadwick Cherry which I've found to be more flavourful and early than a Chocolate Cherry. Ildi, small/tiny yellow plum is delicious and, this year, producing hundreds of fruits. It failed last year but I had spare seed! Sungold a classic orange cherry. Slightly bigger but early and goes on and on, and very tasty - Blooming (change the 'ing' for 'dy' to avoid upsetting a sensitive algorithm!) Butcher early, goes on and on, very tasty (afraid I wouldn't touch Gardener's Delight for lack of taste!)
Beefsteak/large - True Black Brandywine (amazing colour and taste, rather ugly), Tomande, Moskvitch (early and hardy), Amish Paste (massive plum, tall, vigorous and tasty) and Ethel Watkins (vines shortish - 4 foot) are all doing well this year although only the two latter have ripened so far. Dívčí Prs (Czech Breast) proving good too - large yellow orange and quite sweet, good tomato flavour; the nearest I could find at the time to Orange Russian, a massive tasty orange ox-heart type. A bizarre year.
I'm sure that we will all have our own favourite that will simply make your choice harder. Sorry!