My experience is that the Argyrotype is more dependent on the paper than
VDB, so I'd suggest that as more suitable for newcomers.
You will I think find instructions for making the silver oxide from the
nitrate in the archive (if you are at all a chemist you won't need to
bother to look it up) - here it is easier to find cheap silver nitrate
than cheap silver oxide.
I think the main thrust behind the Argryotype was that Mike Ware had
found he lost the highlights during processing with conventional
formulae. I didn't seem to get this problem.
The main cause or fading in all iron processes is the failure to remove
iron salts from the paper due to the formation of insoluble iron(III)
compounds in alkaline solutions.
Peter Marshall
On Fixing Shadows and elsewhere:
http://www.people.virginia.edu/~ds8s
Family Pictures, German Indications, London demonstrations &
The Buildings of London etc: http://www.spelthorne.ac.uk/pm/