I just uploaded some pictures of character counters mounted on Tessel Tiles. These tiles work great and the size is just perfect. The colors are very very close to perfect. I used orange for Colonial, green for Ancient, red for Future and blue for Modern. I did not mount the pets or sentinels because I wanted the lesser pieces to look, well, lesser. There are unused yellow hex-tiles in the bag if you want to go that route. A _key_ thing that makes this mounting method more useful than some is that the AGE of the character can be noted more readily since the color of the tessel tile matches the age.
The tiles also come in white (but not black) which I used for the white Guardian markers and the Jump Gate. I used some spray spaint and a wide point "Sharpie" (for touch up) to make black tiles (from blue - worked great) for the black Guardian markers.
These high quality and accurate cut tiles are cheap ($2.00 for a bag of 350) and come with square, triangular and hex shaped foam pieces. The square and triangular pieces make great markers for other games as well. I made a one time purchase of 15 or so bags and I use them all the time in many many different games. You could even glue the squares together if you want foam cubes (Though I have not done that.) I think 5 bags would be many more than enough to mount the Characters and Guardians.
I edged the pieces with a "Sharpie" It makes them look more finished. I suggest you do this before mounting to prevent bleeding. I used a standard "glue stick" that you can get at any office supply store to mount the pieces.
The playability of the game is much improved after mounting the counters this way.