Buying roof bars and roof box

Herzlos

As mentioned, roofbox.co.uk is great.

I went through 2 sets of cheap eBay bars and returned both as being damaged, and instead went for a set of Atera ones which are thule compatible but were much cheaper.

With raised roof rails you've got a lot more choice since more or less any of the clamp style ones will fit.

Since summer is over you'll probably be able to find plenty of roof boxes available cheap because no-one likes having to store them.
What I usually do is buy one, use it for a while and then sell it on, which is a bit more hassle but cheaper than hiring.

Ditzy_Mitzy

We've got a Karrite* roof box, which is excellent and was much cheaper than the equivalent Thule.  It's nothing fancy, but it doesn't seem to leak and has never given us any trouble in the 20 odd years we've had it.  I expect it will last another 20 if looked after.  

*Having looked, Karrite are made by Thule, so that's probably where the quality comes from.