I'm not sure, but I think the new line of Korkers are not cut wide. The felt on my old Korkers wore out. I wanted to buy new felt soles, but I learned the new Korker soles will not work on my old boots. Instead, I bought a set of Rock Treads and put them on my Korker rubber soles.
Having used both steel and aluminum studs, I think aluminum, which is softer than steel, provides the best traction other than felt.
I am not sure why you want a light weight boot. To me, the weight of the boot is not that important, unless you are going to do a lot of hiking. I also feel that wading boots are important. A fall in the river can be very, very serious; that's why my next pair of boots, in spite of the cost, will be the Patagonia with aluminum studs built in. (These boots, I believe, are cut wide.)
BTW, if you go the Rock Treads route, I recommend that you use Gorilla glue before you screw them in.
Randy