There isn't really much choice.
There isn't any special plan offering what you seem to be looking for.
There's just the standard €12.99 plan or the €10.99 student plan if you're a qualifying student.
You may qualify for the €3 for 6 months discount on the €12.99 plan if you sign up soon.
Membership plan bundled EU/UK roaming allowances don't make all calls/texts free while roaming.
Just those that would be free/covered by your membership plan if you were in Ireland - e.g. calls and texts to Irish numbers.
You may still need cash credit (and an active membership plan) for some services while roaming in the UK.
E.g. texts/calls to UK numbers since they're still international calls/texts even when you're in the UK.
If you need to contact 48 support about this then see the links in my signature below.
