Tech2Win is just what it says... a Tech 2 emulator running on Windows. For all practical purposes the laptop running Tech2Win and VX Diag or an MDI is a Tech2. Since your PCMs are 99-2002 vintage the Tech 2 is the best diagnostic tool you can get.
If you need the GM NAO 33.004 flash card image for Tech2Win go to the Tech2 Wiki and register as a user.
http://www.tech2wiki.com
GDS is the diag software for GM stuff after about 2009 or 2010. You don't need it for this project.
As far as TDS goes... VXManager is likely the same deal as the Bosch MDI Manager. Drivers and hardware settings for the VCI. When you get to the step in the Delco TDS web menus where it asks what interface to use pick VX Diag.
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1959 M35A2 LDT465-1D SOLD
1967 Dodge W200 B383, NP420/NP201 SOLD
1969 Dodge Polara 500 B383, A833 SOLD
1972 Ford F250 FE390, NP435/NP205 SOLD
1976 Chevy K20, 6.5L, NV4500/NP208 SOLD
1986 M1008 CUCV SOLD
2000 GMC C2500, TD6.5L, NV4500
2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263
2009 Impala SS LS4 V8
RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
Please include at least the year and model in your threads. It'll be easier to answer your questions.
And please let us know if and how your repairs were successful.