Buying a VW camper is much like any other vehicle purchase.
You can buy with cash - nice if you can afford it.
You can buy using a credit card - nice if you can afford to pay it off.
You can buy using a loan - not so nice and could work out expensive.
Credit cards are useful for the out of pocket expenses which you will inevitably incur with any old vehicle. Personally I try to find a card with an interest free introductory period to take advantage of. If this is not possible the next best thing is to find a card with an interest free period on balance transfers.
Incur all your expenditure on your day-to-day card (preferably one with cashback or reward points) and then transfer the balance to the interest free card.