Technically, theres no best commander, but some are definitely better than others
Over the years, new card types have been introduced that look quite a bit different than your standard Pokemon card
It will also retain any subtypes it may have, such as Forest or Island
If youve not played with cards like these before, theyre worth picking up mid-pack as insurance in case you later end up with splashable cards in that color
Black's tutors allow you to ignore this by searching for any card you like, completely unrestricted, and placing it directly into your hand, or on top of your library
So, if you want to use Bounsweet in the second fashion that I mentioned, I would recommend making your Grass type deck, quick or free on the retreat costs, or have a Grass type deck that has Pokemon doing damage to their own Pokemon, that way you could try and get Bounsweet in the active Pokemon spot for a turn or two and heal your own Pokemon