Welcome S & A. We have travelled with bikes on the back of out 4 Eribas, 2 x Tritons, 1 Troll and 1 Famila. If you use the search facility you will find lots of useful info, but to summarise.
Eriba no longer advise this set-up, but if you stick to 2 bikes and watch the noseweight you should have no problems. I have fitted 3 of the carriers and would always advise bolting them through the steel framework for you top fixing and a spreader on the inside of the van wallboard with spacer tubes through the insulted body for the bottom fixing. Fiamma and Omni make various carriers that will fit, but you have to be a little creative, practical, methodical and very accurate in the fitting. If you can manage this you are onto a winner.
The last rear carrier I fitted was using an adapted Trigano motorhome carrier. I decided on this as it meant I could bolt through the waist-line instead of over the rear window. This keeps the weight lower and still allows the window to be opened. I made a jig up so that I got the drilling angle correct.
I also cut a piece of 10mm steel plate and mounted this and a towball on the jockey wheel mounts allowing me to use a Thule towball mounted carrier as an alternative if I wish.
Please feel free to PM if you have any questions