Which saddle for London to Paris

I don't know about shorts. but I'd go for a Brooks B17.
Anne Mustoe rode round the world twice (and more) on hers.

What bicycle do you ride, and is it still the same one?
Yes, it's still the same old faithful, though it looks different because it's been resprayed and is now bright orange instead of sea green. Parts of it have been updated over the years, as cycle technology has advanced. But what I shall never update is my wonderful Brooks leather saddle. All those thousands of miles and I've never once been saddle-sore!

The bike is a Condor, (Condor Cycles.com) built specially by Monty Young and his team for my first journey round the world in 1987. It's light, but very strong, and I love it.

Specifications:-
Frame Reynolds 631 Mixte, butted tubes
Transmission Shimano Deore. Front 28-38-48. Rear 13-15-17-20-23-26-30.
Wheels Deore LX hubs
Mavic TS19 rims
DT stainless steel spokes
Tyres Continental Top Touring 2000
Handlebars Humpert Pro Bars
Pedals Shimano M324 SPD
Saddle Brooks B17 STD
Mudguards SKS
Pannier Rack Blackburn Ex1

http://www.annemustoe.co.uk/faqs.htm