Look else where. Having attempted to work alongside and train them, I can verify that they don't actually have a role / do much. If you're lucky, you may blag 1 week a year in JHQ (whilst ARRC is still there) to act as a watchkeeper on exercise but otherwise nothing. Depends if you want the opportunity to deploy / undertake a decent bit of training.
(Having worked with one of them, I can't believe I'm actually about to say this, however) you're better off joining one of the RMP (V) Coys in either 4 or 5 RMP. 5 RMP is probably better as her 2 regular sister Coys are in Germany and there'll be more scope to exercise out there than with 4 RMP. Either would probably nominate you for an Op trawl if that's what you're after.