Tell me about it. I'm so tired of changing the sheets every day. I actually have the plastic mattress cover on upside down under his sheet so I don't have to wash that, too. Cloth side is down so when I take the sheet off, the plastic is right there and I can just spray it directly with lysol or febreeze or whatever I have handy.
Here's a link to their page: http://www.rpromise.com/tena/pads.html
I wonder if you called them they might send you a sample before you spend a lot of money on them.
My kids are seriously deep sleepers. We've tried getting him up at midnight and 2am and he's STILL wet in the morning, though usually not completely drenched. I can put him to bed at 8 and he's wet when I get him up at 10 or 11. I think he just dribbles out a little bit all night long instead of the sort of daytime control where you save it up and go all at once, and I have no idea how to get him past that. My 5yo is not night trained, either, but he's dry about half the time.