-
3 hrs motorway ride + pillion = >500c + fairing
IMO there is no escaping this.
My gut says try and get a fast 125cc now to gain experience and use to practice for your test. To get a full license you'll have to ride a 500-600cc bike anyway.
Something like a CB500X could be a good shout. Easy to ride. Practical. Not too heavy. Can't remember what the wind protection was like though. Engine's not as smooth as something like a 600 Bandit, but imo it's an easier starter bike. Kawasaki ER6F also a good one to look at.
Just exercise caution, don't be a dick, and test ride everything you can.
-
Cb500x is an excellent suggestion. As is the older counterpart, think it's a cb600? Around 2007-2012 sort of age, and some fairings, pillion works OK on it, comfy for long distance and they are in a low state of tune, so healthy on fuel and last forever. Mate bought a 2009 with about 85k on it and rides impeccable
I do think it might be a bit of a jump too to hop straight on a 600. I'm 25 yeah.
I probably should have been clearer with what I'd use it for which may have helped. It'd live with me in London but I'd continue to cycle commute. It'd be for weekend rides, going to the girlfriends parents in Sussex and occasionally blasting up home to Shropshire on the motorway approx 3 hours ride/drive
Edit: Often with the other half on the back