I consulted this site for ideas: http://spacecolonization.wikia.com/wiki/Space_Colonization_Wiki
Also this and its references: http://en.wikipedia.org/wiki/Colonization_of_the_outer_Solar_System
And this discussion: http://www.newmars.com/forums/viewtopic.php?id=7070
Jovian satellites and radiation exposure I found (different than yours):
Callisto: 0.01 rem/day
Ganymede: 8 rem/day
Europa: 540 rem/day
Io: 3600 rem/day!
Thebe and inner satellites: 18,000 rem/day!
Callisto is in a zone where it benefits from Jupiter's protection in terms of cosmic rays, but doesn't get a radiation bath requiring massive amounts of shielding. It's also closer to the edge of Jupiter's the gravity well than the inner satellites. Ganymede does indeed have its own magnetosphere, but there are questions as to whether it provides the amount of protection you indicate (consensus seemed to be much less). While it is true that you can burrow down in the ice/rock and find protection from much of the radiation exposure (even on Europa), it's still much easier to colonize Callisto than Ganymede (lots of water ice, geologically stable, etc.), which is why NASA picked it as a potential target for a manned expedition.
Also this and its references: http://en.wikipedia.org/wiki/Colonization_of_the_outer_Solar_System
And this discussion: http://www.newmars.com/forums/viewtopic.php?id=7070
Jovian satellites and radiation exposure I found (different than yours):
Callisto: 0.01 rem/day
Ganymede: 8 rem/day
Europa: 540 rem/day
Io: 3600 rem/day!
Thebe and inner satellites: 18,000 rem/day!
Callisto is in a zone where it benefits from Jupiter's protection in terms of cosmic rays, but doesn't get a radiation bath requiring massive amounts of shielding. It's also closer to the edge of Jupiter's the gravity well than the inner satellites. Ganymede does indeed have its own magnetosphere, but there are questions as to whether it provides the amount of protection you indicate (consensus seemed to be much less). While it is true that you can burrow down in the ice/rock and find protection from much of the radiation exposure (even on Europa), it's still much easier to colonize Callisto than Ganymede (lots of water ice, geologically stable, etc.), which is why NASA picked it as a potential target for a manned expedition.