I think 160 is probably a push, but after some declines you'll probably be okay. I have been to a wedding there but can't remember the exact number of pews, I think you can fit 4, maybe 7 people in one at a squish? Bonane has more rows I think but less wide, so maybe 5 each side.
Dawros is a beautiful setting, but depending on the time of year maybe that's less important?
Bonane is a bit further out of Kenmare, but I don't know where that is in relation to your venue. As far as I remember there was no bathroom there either!
Holy Cross Church is another one in Kenmare that's absolutely beautiful and can fit huge numbers, but the parish priest is very strict on the church music, so bear that in mind.
I think I have photos from inside all of them so PM me if you'd like more info!