Being the non-knitter that I am, I don't have any advice except to ask, the two craft catalogs I get usually sell the pattern separately from the kit if you want it. Will the Irish site do that?
It looks to me like the Clan Arans sweaters are sent to you fully made, not as kits, although it's entirely possible that I just missed that link somewhere.
Alice Starmore's "Aran Knitting." I love her "history" of this genre.
Since Alice is the designer, the patterns are, of course, awesome.
I just emailed you a message about the son of aran pattern online, hope this helps. My daughter used to live in Peterborough, by the way. Great town.