With the new fuel tanks that can be fitted in internal compartments, the clipper might just be an option.
The clipper has more than enough compartments to spare to fit extra fuel tanks. And with a lvl7 scoop, it sucks the life out of a sun and makes it a black hole!
So fuel is not a problem anymore.
But then again the jump range is horrible.
I tried some exploration in a clipper but quickly decided that the Asp is a way better ship for that. But that's another topic.
Between the clipper and courier the jump range is not a very big difference.
The cockpits I can't compare yet, but they both have open top views.
For pure exploration this courier
http://www.edshipyard.com/#/L=707,mpV0Wg0Wg,2-3m3m4s2C3m3m5A,4zM5DI7O20Iw2UI2jw
It has all you need out there.
Just don't jump in into any USS's.
Or a clipper
http://www.edshipyard.com/#/L=703,mpW0Wg0Wg,2-8S8S7_8S6u8S6k,53c5H_0M2mpU7Pc2jw2UI
And you could give it an even bigger fuel tank!
You could also equip a fuel transfer limpet controller so you could help fellow explorers who ran out of fuel.
So the extra slots of the clipper weighs in it's favour.
You could argue about weapons and shields and more fancy stuff, but if you explore more than a few k ly's away from "civilized" space, you really don't need that stuff.
(I've added the shields because I just want to make sure that when I dock I'll end up docked instead of in 1000 pieces floating around in the station.)
But in the end, the choice is also your personal flavour. Remember, you'll be living in there for months on end, so it better be a nice view (and sound).