Robin,
I would recommend you get a small adaptor cable (also known as a patch lead). from your Westflex into the back of the RB. You don't want to be causing a strain on the back of the RB by continually connecting/disconnecting because of our frequent thunderstorms over here.
There is no difference in performance. I use an RG58 patch lead. Not sure where in Spain you would be able to obtain it. Best to 'Google' and perhaps try from the UK. Delivery costs should be minimal as it is only a small item. If you go to Westlake they should be able to supply one with the correct connector already fitted.
Ian