Heather asked which potty we had bought for the boys to use. Being as frugal as I am, we bought one for $10 at the multiples club sale. It sings and makes the flushing noise, except we never put batteries in it. We also scrubbed it down with clorox before use!
And then we thought we needed another one, so the business owner (our neighbor) across the highway was having a yard sale and I got it for $3. It was a plain jane kind of potty. We used both for awhile but now the boys are too tall for them, especially the musical one. They will be three in March and are 44 and 45 inches tall already. We have the plain one in the closet as an emergency spare and sometimes on long trips it accompanies us with a plastic bag and a towel underneath it in the back of the Durango.
We also have a soft potty seat (Bob the builder) for our regular toilet.
I was going to link to the potties but it seems I cannot find them. They must be outdated. I also think the simpler the better. MY boys are easily distracted. That was the main reason we never put batteries in the one that was musical. I hope this helps.