Buying Technical Manual/CD

[Skulz]

In the owner's manual there is a listing about purchasing a tech man for $120 or so and then a transfer case man for $50. I know Klaus has some service cds (not sure if they are Hummer specific or just GM). Has anyone purchased the text based manual and how much/where? Also, where to get a copy on CD /w TSB updates (ie how do you get updates with only text base?)?

Thanks in advance,
-Skulz