Hi there,
My son recently made the step up to training pants.
Training pants are typically thick cloth underwear. They're designed to catch little leaks, so that when the child has a small accident whilst getting to the potty, the trainers keep the little drip contained. (I say contained as compared to thinner child's underpants, which hold nothing at all.) Training pants usually have layers of cloth much like a diaper, but allow children to practice pulling their underwear on and off, which they will need to learn. As far as training pants go, you can find them just about anywhere--I believe Gerber makes some, and it's likely many in-store brands exist. We spent some money and purchased the Hanna Andersen ones, because they are thicker and the fabric holds up very well. It was an investment, and as we are constanty washing these trainers, a good one. And yes, my son can feel when he's wet, because while they hold little drips, a full-on accident will still result in wet pants--a great motivator for staying dry.
Pull-up style diapers are just that: diapers. Some families like to use them, and they can be convenient, esp. if you are on the go. When I nannied children who were partial to pull-ups, I often limited their use to trips out of the house; otherwise, if they wanted a diaper, that's what they wore. I wish pull-ups had never been invented. Truly. They tend to prolong/delay toilet learning because the child cannot feel themselves be wet. (The fact that they had to add a chemical to make the diaper feel cold to signal the child is pretty telltale.--and do we want our kids wearing a chemical near their reproductive organs?) Children confuse the styling of the pull-up with underpants, too. We personally use a paper diaper for out of the house trips or overnights, and offer our son training pants or cloth diapers during the day at home.
If you are concerned about leaks and protecting the furniture, you can always use a diaper wrap over training pants, or rubber pants that typically go over cloth diapers. The point in all this is to let them experience the wet trainers and diapers so that they develop their own motivation to stay dry. Pull-ups are truly more convenient for parents in the short term, but deprive the child of the natural consequence of wetting themselves. Oh, and as for the mess, we just shake out any solid waste and then launder appropriately. (I should add though, that my son is highly motivated to use the toilet, so we don't have the mushed-in poop some parents have to deal with. I do know some moms who just bought lots of cheap trainers and threw away the poopy ones...each to their own, eh?:))