Any question answered...

That combo looks fine but if you want Thule; the way I did it was as follows. Go on the Halfords or Thule website and find out the relevant part numbers you need and then either search for them individually on ebay and/or find other cars that take the (same feet or) bars that you need. Then instead of searching Volvo V50 roofbars you might search Vauxhall Zafira (an example out of thin air) and find someone selling used what you need but described under a vehicle you haven't got. I'm not sure that makes as much sense on the screen as in my head but there you go.
I had a set of bars just like your example and it was like a full-on Hammond Organ at 45mph as the wind whistled over the holes. judicious use of masking tape cured that.