Welcome to ECF!
I searched Amazon for the e-liquid you posted and it doesn't show up for me (must be just in the Amazon UK site) so I can't speculate as to whether it is good or not. The only vendors I know of that serve the UK are
totally wicked and
liberty flights. They are both legitimate vendors, I think Liberty Flights tends to be more reasonably priced
But there is a UK forum here and if you just make a few more posts you will have access to
that forum. I just looked there and a poster listed some UK vendors:
Cam - UK GG Stockist
Toby - Ivapour
James - Paradise Vape
Kev - FreedomVape
Aaron - Ecigwizard
Lisa - Cloud9
Tim - Moju Republic
Liberty Flights
Enjuice
Totally Wicked/TECC
OK Smokey