Ireland in April can be quite beautiful with early spring colours especially on the west coast in the Burren area. The Burren is a vast area of limestone pavement, basically flat limestone rocks with numerous wide cracks in them. I have to say that they are not easy to photograph in black and white in bright sun. My advice is to get out there in the rain and be prepared to get a little wet making photographs of the wet rock.
Connamaragh, just a little north of the Burren offers a more traditional landscape with soft rolling hills and moorland. This can be good in just about any light with soft mist being my favourite.
The beaches of Donegal are interesting as are the small islands just off the coast.
If you enjoy making photographs of people Ireland is the place to be for they are the most warm and friendly people that I have ever met, photographed and had a pint of Guiness with. They will be very happy to talk to you and cooperate with you in making photographs.
AS to kit, I would stick with what you mentioned in your post. Film for me would be FP4 medium format and TriX and Ilford Delta 3200 for 35mm. The 3200 would be used in making available light photographs of the people in the many pubs that you just cannot pass.