Best potty chair for boy?

SCBride_Oct2004

We have the Baby Bjorn potty seat ring that goes on the toilet.  All summer our son was peeing on the potty several times a day using this.  We didn't force it at all and only started when he showed interest, and he actually asked to use the potty and when he'd say pee pee he'd also say let's go and he took off to the bathroom on his own.  He flushed, said bye bye pee pee, clapped and cheered for himself.  And every night before his bath he peed on the potty too. 

About 2 months ago he began flat out refusing to use the toilet anymore and screams for a diaper if he sits on the toilet.  Yet at the same time, he's not always happy about diapers either and either won't let us put one back on or he's pulled his diaper off a few times after he's peed or pooped.  He told me his diaper hurt today so I took it off since I've heard going without a diaper can help with potty training. I knew we'd probably have accidents and of course he actually peed and pooped on the floor today, gees that was a first.

He's pretty tall (90th percentile) and was 36.5 inches tall and 32 lbs back in September at his 2 yr visit if this helps.  I've read some potty reviews that said they weren't good for boys or weren't good for tall kids for various reasons.  I'd like to let him give a potty seat a shot to see if that will help, especially by leaving it in the family room where he spends the most time.  I've read great reviews about the Baby Bjorn potty chair so if anyone hear has it I'd like to hear about it too.