J.V.
I clothed diapered my kids, so I was able to just use our regular diapers till they were ready for trainers. I am a big believer in letting them have accidents.
If I was you, I'd just use the Gerber's, but him in thick pants, and deal with the mess. Or let him run naked. Naked is the best way to train fast, if you ask me. Both of my kids were trained around 21 months, including night time.
Sorry that I can't suggest training pants, I decided they were a waste of money and that I could handle some pee on my floors.