FYI, the Bumbo potty seat is AWESOME with babies! I started my 2 month old on it this last week. While I still hold her up, it has made it really easy. I have EC'd from newborn stage before without it, and this is soo handy.
So, in case anyone is wondering what gear to buy, consider this. I went back and forth and then took the plunge before DD was born and am glad of it. If you have a boy, you'll probably have to cut the seat a bit, so that'd be harder to re-sell if it doesn't work well for you. But that is just my thinking, I don't actually know.
I didn't know there was a bumbo potty seat! My dd1 definitely thought the bumbo (non-potty) seat was a potty...we didn't have one, but unfortunately, our neighbor did. Fortunately, she was understanding about having my dd pee in it!