A place where to find loads of starkits is https://www.tcl-lang.org/starkits/ .
The sdarchive provides a centralized location where people can go to download a new starkit.
This repository is also designed to work with the sdx update command, so that if you have internet access, you can run:
sdx.kit update downloaded_starkit.kit
and sdx.kit will contact the repository and download updates.