Film and Tracking

It looks like a tracking platform (AKA Barn door mount) will be on my to do list for the near future. I want to get a GEM but for now its on hold due to lack of cash. This should at least allow me to do 2-3minutes on the K-1000. This should be good for a few rounds (or at least until I use up the 6 rolls of Provia 400F that I have)

Longer term I want to get a GEM so I can track longer and guide.

For Large format film I'm no deciding between Provia 100F and Kodak E100G.