Eric,
These work, lots of divers in Canada using them - just stretching them over the rings on the SI Tech or Dive Concept rings. I guess you can also install them instead of the SI Tech gloves (take rings out, etc). The guys from the Pacific Rim National Park Serivce near Barkley Sound up there used these, just stretched up over the rings (you have to get someone else to do it).
http://www.watsongloves.com/product.html?id=219
Also I saw a gal using white heavy duty kitchen gloves in 45 degree water and I was also told heavy duty gloves from Home Depot would work? But these in the link are the tried and true ones.
And I dove with a local gal there whose new SI Tech gloves leaked badly so she had some of these rubber "fish-cleaning" gloves as spares, got the captain to stretch them over her rings for her while she was still partially in the water and it saved our dive -- she said she would not go back to the SI Tech gloves.
Wish I was going!!
I planned to get these gloves to stretch over my Diving Concepts rings but alas I can't go........boo
Have Fun, Carol 