Hi Fred, and welcome to the message board.
It's reaally difficult, as I'm sure you've discovered, to research Irish ancestors. I can't stress how important it is to identify which part of Ireland they came from, especially with one of the more common names. I take it there are no clues in the census' in the Birthplace fields for any of them? One of the best sites I've come across is this one:
http://ifhf.brsgenealogy.com/search.php but it looks like with over 500 birth records for William O'Boyle you'll need to narrow it down a bit.
Sorry I can't help much, but good luck
Phil