Tried that at the Gin festival and it was very nice!And whilst not quite a full blown gin this is nice...
EDINBURGH GIN'S RHUBARB & GINGER LIQUEUR
https://www.ginfestival.com/products/edinburgh-rhubarb-ginger
Call me a generic peasant but I really like Schweppes with Bombay Sapphire - like the extra flavouring of Bombay. Failing that, Hendricks is a nice option.

Pair these with Elderflower Cordial and you've got yourself the perfect G&T!
I love a gin with elderflower, and if the dominant flavour is going to be elderflower it doesn't matter so much which gin you have in my opinion.
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.The Lakes Gin. Only gin I've been happy to drink neat: http://www.lakesdistillery.com/shop/category/gin/
We stumbled across the Lakes Distillery a couple of weeks ago while up in the Lake District. Next time we're up there, we're going to book a tour.
I do believe that a Gin needs to be overproofed for the flavours to really work.
Blackwoods do a 60% gin. It makes a fantastic Dry Martini - bloody lethal but fantastic.