I rode the Beara/Dingle/Iveragh peninsulas in September - about 600km all in and if you're lucky with the weather some of the nicest riding you can get - a drop dead gorgeous view round every corner, plenty of accomodation options and good pubs. Flew in/out of Kerry airport, so straight off the plane and into the hills.
It's pretty easy to avoid most of the busy Ring of Kerry section by using the back roads which often hug the coast more. I'd recommend adding the Skellig/Valentia Island section, plus some of the more inland sections like the Black valley, Caragh lake and the Gap of Dunloe. The area itself is pretty small so it's easy to adapt a route on the fly and add in some detours. Can't recommend it highly enough, but then I've done three trips in the last two years and haven't seen a drop of rain!