I've been searching the net for a comprehensive list of drawings of IC
> packages, specifically, all things "SO" (ie, SO, SOP, TSOP, SSOP, TVSOP,
> etc.). What does come up are lists of packages, but no drawings.
>
> I need to have dimensions listed as well, similar to what is typically
> provided in datasheets.
Many packages are just "nominally" dimensioned. Manufacturers often come up with "modified standard packages" with slightly different dimensions, etc.
Likewise, if you are interested in land patterns, the recommendations for these often vary from vendor to vendor.