Yes, my husband and I did a three-day trek around the Ring of Kerry in 2006. It was one of the most amazing experiences of my life (didn't hurt that it was my honeymoon :)) We rode pretty much 7-8 hour days, with a stop for lunch, and the company arranged B&B stays for us each night and took care of the horses overnight.
I know you said you have a limited geographic area, but Ireland is a compact country, so I would suggest if it's something you really want to do, think about renting a car so you can hit a destination like County Kerry, which just isn't that far away in the grand scheme of things.
I think the pictures speak for themselves...
Climbing the hills:
Hitting the beach:
Lunchtime break for the horses:
Group photo (we had a mix of Americans, Canadians, Brits, Germans- and as you can see, young and old, male and female. It was a nice, friendly group, but the group time wasn't annoying or overwhelming).
Heading back up from the ocean on our last day:
Also, the title of your thread reminded me that there is a PBS show called Equitrekking
, and they did an Ireland episode
(I think you have to pay $4 to watch the full episode on YouTube-but this is a two minute trailer). Might help target your search.
Bottom line- if you've been saving for this and dreaming about it for so long, try to make it the trip you're really dreaming of. For me, that met the hills, the ocean, the B&B experience. Hope you have an amazing time.