Bear in mind, you will lose your irish channels - and i'm assuming you've already been with them longer than the minimum contract period?
If you need the irish telly, bring everything with you - thats assuming you have not agreed to the box being hooked up to the phone. If you have, ring them up and tell them your going to use your mobile only - and your getting rid of the landline. Technically, this (bringing irish sub to uk) is against your agreement with them - but if your paying your sub, wheres the harm? On that basis, they don't need to know your moving..