Those Cherokee Purples look and sound terrific, but where I live, if I plant out on last frost date, mature date to first frost date is 10 days, and that's not even at UK light levels.
Maskotka, a Czech large-cherry is my present favourite, but I'm trying a few cultivars new to me this year: Harbinger = UK heirloom standard slicer; Stupice = another Czech open-pollinated variety, cold tolerant, golfball sized and well quoted for flavour; German Orange Strawberry = it's name says nearly all, but it's an early ox-heart type; Mortgagelifter = US heirloom which may just prove to be best open-pollinated beefsteak option for UK (tell me more you fellow members from N.America)
Black Cherry = No guesses and San Marzano = cooking plum tomato.
All these in addition to my 8-10 baskets of Maskotka.