"Would a netbook with a touch screen overlay seem affordable and FLOSS
friendly ?"
i guess it depends on the netbook
there are definitely freedom friendly net-books
you can find a list of hardware including netbooks that’s reported to work
with freedom software here:
https://h-node.org/hardware/catalogue/en
"but I am a little worried about how long it would take to set up."
you can find the instructions for the tablet i mentioned here:
http://redmine.replicant.us/projects/replicant/wiki/GalaxyTab270P31xxInstallation
as long as you have basic knowledge of how to use a terminal for this model
of tablet it dose not look very intimidating
but if you can just use a netbook then it may be cheaper and easier to setup
