I almost forgot, welcome to the forum.
Choosing waders is a hard enough ordeal when you live in the States. It will be even harder from Ireland. You need to buy the best you can afford.
The most breather waders are those that use Gor-Tex. I had a test on the breathabilaty of waders and the Simms was the best by quite a bite. That test is a few years old and new waders may be better now. Besides the breathabilty of Gor-Tex you are assure that the construction is good. Gor-Tex license companys who use their technology and they must meet Gor-Tex's standards for construction. I don't think I would buy any wader that is made in China.
Most waders are made over seas and they use a membrane construction but the quality may be questionable. Waders are one item that as you pay more money you get more advantages such as better breathabilty or multiple layers of material. Many wader makers use multiple layers of material to increase the toughness of the wader. For instance less costly waders may have three layers of material in the legs. A higher priced wader from the same maker may have five layers of material.
I don't think that anybody will disagree that Simms has a great product and they stand behind everything they sell. I can recommend them very highly. They are not cheap but to many people they are worth it. They are made in the USA.
So to summarize. Buy Gor-Tex and spend the most you can afford. It will reward you with good service.
Here are some to consider:
Simms L2 Gor-Tex 3 layer construction with reinforced knees.
Simms Rivershed Stockingfoot 3 layer with 5 layer front legs.
Simms Headwaters 3 layer with reinforced front legs and articulated knees.