Try the smart broadband offer. If you can get it its an excellent service. I've been on BB with them for the last month now almost and its been very good. Also my phone line failed the line test constantly but due to smart using an upgraded version of DSL BB (ADSL2) our line passes and is fine for BB.
Other possibilites are NTL BB or Irishbroadband. I suggest you try for NTL first as Irish BB service has become very poor in recent months and you will be waiting for a long time to get them to connect you. If NTL is available I would go for that or Smart BB.
If you are sticking to dialup then either UTV or BT Ireland are cheaper for this than Eircon (with an emphasis on con by the way).