The sets all feature the Kellogg's logo on front and back as well as the manufacturer's logo. Upper Deck issued the 2007-2009 sets, with Topps taking over in 2010 after Upper Deck lost their license.
With very small checklists, collecting full sets shouldn't be too hard, and is a project I am considering. On the other hand, singles usually aren't cheap. I should note that my checklists (including spelling) are based mostly on the SCF database.
The 2007 set has 10 cards, with three Japanese players:
- Hideki Matsui
- Kenji Johjima
- Tadahito Iguchi
- Ryan Howard
- David Wright
- David Ortiz
- Ivan Rodriguez
- Alex Rodriguez
- Albert Pujols
- Justin Verlander
2008 again has 10 cards, and three Japanese players. Note that the SCF database is incorrect; based on a bit of research the below list should be accurate.
- Daisuke Matsuzaka
- Hideki Matsui
- Takashi Saito
- Jimmy Rollins
- Vladimir Guerrero
- Manny Ramirez
- Joe Mauer
- Josh Beckett
- Grady Sizemore
- Jose Reyes
I don't have any 2009s yet to check the design, or to even verify the manufacturer. The SCF database lists a checklist of six players:
- Akinori Iwamura
- Daisuke Matsuzaka
- Kosuke Fukudome
- Alfonso Soriano
- Alex Rodriguez
- Josh Hamilton
The last year of issue was 2010, with Topps taking over due to Upper Deck's loss of licensing with MLB Properties.
- Hideki Matsui
- Akinori Iwamura
- Hideki Okajima
- Chase Utley
- David Wright
- CC Sabathia
All in all, a total of 32 cards seem to have been issued. The key cards will definitely be the Matsuis for a set builder.