Unless there is a really good
PR opportunity or some possible benefit of a demonstration to, for instance, special forces, of something that hasn't been done before, I would have thought the chances of getting permission for a landing on an in-service carrier are very slim. If you can find a carrier that has been withdrawn from service and you can satisfy the owner that you won't sue him when it all goes horribly wrong, then you might have a bit more chance.
I can remember seeing either Bulwark or Ark Royal moored in a Scottish Loch awaiting the scrapman's torch some years ago, so after the SDSR there might be one or two becoming available for your plans. A recce first would be a good idea, as FOD on the deck or a lift a few inches lower than it should be, could mess up your day.
The Americans have at least one carrier (Forrestal) waiting to become an artificial reef, but getting permission would be a case of hard work, patience and knowing the right people, and that's if its even got a complete, unobstructed deck.
With a moored carrier you have the added fun of wind direction, which could be from anywhere. Try doing some approaches to a hilltop airfield (e.g. Compton Abbas or Nympsfield) in turbulent conditions and see if you still want to have a go at it. I've seen a glider doing a 70 knot approach which dropped a wing 45° on the way in to the latter. Fortunately the pilot recovered it.