Diapering an 18 month old

When we first set out to cloth diaper I thought the one-sized diaper was the way to go. Most are made to fit until the child is 30-35 pounds and they adjust nicely for that time period. Unfortunately, we've hit a bump in the road, my almost 27 pound toddler is growing out of most of his one-size diapers and he says "no-no" to the toilet. What to do? Do I invest in more sized diapers? Well, to start with, I bought a couple large diapers (I believe I got 2), they're both designed for 25-40 pound kiddos. I've also gone through the diapers trying to determine what will last. I think that my Happy Heinys, Knickernappies, and Fuzzibunz will make it to the potty training phase. I do not think the Bum Genius 3.0s will, nor do I think the Gro-Baby will. I am still torn about the Haute Pockets and the Dream Eze (size large). My newest diaper the Mother-ease diaper is nice and will probably last through potty training, however I am not a fan of covers, it just adds bulk. But here's a cute picture of the little man in his newest diaper.