Advice please on satellite dishes and receivers

This will be our first full year as Motorhomers and we want to be able to view Sky TV both in the UK and France.  Does anyone have experience with 12v TV's with built in sat receivers? Are sepatare boxes better?Also, do the Sat. dishes that can be put on a table do a good job or not worth the money?  Advice would be much appreciated.  We understand that systems don't come cheap but want to make sure we spend the wisely.  Thanks