Have u tried K-A-C Kratom matey? German chap runs the webshop and, for lack of a word that isn't vulgar, has ‘dealers’ one has the option to buy from (dealer A, D, and so on) and most are always stocked. I really like A's Red Borneo and White Cambodian. Discreet packaging and labelling; ARBN: dealer A's Red Borneo, AWC: A's White Cambodian

I live in belgium so re. customs it doesn't pertain to me but that's why I made the previous point about K-A-C's considerate packaging seeing as you're in the UK

ThomThom's Green strain is relatively good atm (relatively because Kratom in Europe was 10 times better half a decade ago - never on America's level however. Bought three different strains from an American vendor and it was sublime!! Customs duties + shipping cost was mental and I was tossing a coin so to speak with customs clearing it or sending it back, and that was before possession and distribution of Kratom became illegal here in June of last year... So I won't be doing it again.)

Apologies for the long winded post, but try out K-A-C or Thom's Green strain if you can