Are we talking new shape Berlingo here?
If so there are 2 versions. The one that fits the Multispace and the standard van is the one that is called the L1. The L2 is for the long van(I have only ever seen one long van and that was in France. They are easy to identify because the extra length is a bit added on at the back)
I bought my towbar from ebay for about £65. It has a flange fitted towbar.
Witter make some of the best aftermarket tow bars. You can go cheaper but if you are towing a Caravan, Witter.
Electrics are best left to a professional fitter and on a new shape, get the dedicated electrical kit to (hopefully) avoid all kinds of fun and games.
Swan neck towbar does look neater than flange type though, Bosal, Brink etc.