Couple of points:
1. the 13 pin electrics with my Tow Trust do not swing up out of sight - unlike Westfalia Tow Trust do not make electric kits so it will depend on which electric kit will come with what you have priced up, as to whether they swing up out of sight or not I suspect.
2. The price you have for the Tow Trust and electrics seems high. The bar itself is around £450 so where you are buying from look like they are charging you a lot for the electrics.
3. It won't matter to you because you are using only for a bike rack, but for completeness the standard Westfalia electrics do not come with the caravan fridge pin wired up in the 13 pin socket, you have to purchase a separate Westfalia kit to add to the wiring. The electrics on mine (made by ConwyAG) did come with the fridge and battery charging pins in the standard kit.