I got Dynmap working with tekkit lite (+ other mods)
Dynmap-1.6-forge-6.5.0 for modified version of tekkit lite 0.6.1
There are instructions to set it up here:
https://github.com/webbukkit/dynmap/wiki/Setting-up-the-Dynamic-Map-plugin-under-Windows
Instead of pluggings, the dynmap zip goes in to mods.
If you want to access the map externally, you will need to portforward the dynmap port (default 8123)
You can bluff a link to the map by doing something like this:
<a href="/?worldname=world" onclick="javascript:event.target.port=8123">