Commonwealth troops are not very well represented by manufacturers. Canadian uniforms are so similar to British, you don't see them much. There are a few Australian sets and fewer New Zealand sets. I don't ever recall seeing South Africans. I also assume that the manufactures don't see much demand for them.
BTW, there is a company called Hiriart which hasd a least six (none are WW II) Canadian sets. They include the 22nd Regt, the Royal Canadian Regt, the Grenadier Guards, the Ontario Highlanders, and 2 sets of NWCMP.