I went a different route. We used Charlie Banana training pants. They come in tiny sizes (small is 9-14lbs!) and have a waterproof top layer, and an organic cotton inner layer with a terry soaker pad. They would occasionally leak, but generally if you're ECing, you're only going to have smallish misses. I bring my son to work with me, and couldn't deal with pee all over everything if he did go.
He's now 15 months old, and we've been adding plain old Gerber training pants (non waterproof!) into the mix. He's a pretty big boy (25lbs), so the smallest (that I've seen) pants (2T) fit him, but do slide down occasionally! :P
Mom to E(11/92), H(10/95), C(4/98), S(12/00) and M(4/13)