SeaBass
Here are some thoughts.
3/8 thickness for GTAW is overkill anyhow unless its pipe and then D1.1 would not be the best choice again.
I think (I'll be corrected if I'm wrong) that D1.3 has prequalified procedures and is targeted for steel thicknesses more suited for GTAW.
Also AWS sells SWPS which could be reasonably used.
If you are a tech school than I would encourage you to consider becomming involved in the AWS SENSE
program
http://www.aws.org/w/a/education/sense/The AWS SENSE Program has good a GTAW Curriculum guide and member schools are supplied with SWPS for Carbon, Stainless and Aluminum GTAW as well as SWPS for SMAW, FCAW, GMAW (short circuit and spray) steel and aluminum. That alone is worth the price of membership.