Post-war vehicle related (sort of) question.........

[maple_leaf_eh]

The Oshawa Tank Museum has standardized the green Goretex jacket as its "uniform". If you ask them, you might find who their recommended supplier is. The green combat coat went out of service in the early 2000s. Good luck.

The surplus clothing market is not bulk items, but individually identified pieces. You find strange things and unexpected sellers posting on Facebook marketplace. Sometimes you'll get a private seller who bought a tri-wall of textiles, and is pulling them out to sell by the each.