In reply to gavjwp:
> I'll be mainly onsighting routes. I dont want to redpoint / work routes.
On the basis of your requirements (not much use, not much working routes) I would buy thin and cheap.
10mm ropes are definitely on the thick end and there doesn't seem any need for your requirements. Decathlon do cheap 9.5mm and 8.9mm ropes, 89.99 and 109.99 respectively for 80m, which look pretty good for what you want. I haven't used them and reviews are a little mixed regarding longevity / wear but doesn't sound like that should be much of an issue for you.
For info I've used Mammut Infinity (9.5mm) for my sport climbing rope over the last few years and think they're excellent. Relatively light, handle pretty well and ime wear very well - used for lots redpointing and working routes over number of years. But at around £160 for 80m seems like a lot extra to pay for stuff you don't seem to need (at the moment anyway?).