I am not familiar with these specific programs.
Think about the part of the country or the biome that interests you most. Usually, a university has more GIS data about the area where it is located. If you are more interested in Alaskan biomes, go there.
Also, you might write "Esther Worker " email@example.com and ask about the Denver program. She is at ESRI's regional office near Denver.
(602) 481 2596
200 W Washington St (12th Floor)
Phoenix AZ 85004