I’ve put a Westfalia on my T5 – although not a removable one. Look up PF Jones as they seemed the best on price & range. They are not difficult to fit- although it depends on the year as I believe later models need the canbus updating for the electrics & rear parking sensors etc. Mine is a 2004 so no problem.
Also You have to remove the rear reinforcement beam to fit the tow-bar beam which is shorter & left the outer parts of the rear bumper vulnerable in a crash. Ther rear beam can be fitted around the tow bar beam but does need to have some parts cut out to clear the tow bar beam & only fits on 2 of the 4 original fitting bolts – but this is still pretty substantial.