It's certainly possible. All you would need to do is make a new intake joint to suit the weber face like this:
This pic is from the Link Automotive site, and is not the SC12 kit, but the same basic rules apply. From what I've seen and my talks with Ben '92' about the SC12 kit, it mounts "relatively" the same. By that I mean everything goes in much the same place, just different mounts/flanges to suit the different chargers.
As for using a weber for supercharging, well umpteen years of motorsport says it's pretty damn good. I'm currently looking at using a weber on my Suzuki Sierra which I'll be dropping an AMR300 supercharger onto. Difference is I'll be running in a blow through set up which means the carb has to be pressurized to stop floats crushing and excess fuel everywhere. No need to do this on a suck through kit.
Ben recommends using an HIF44 carb. As far as I know, the main reson for this is because of the new position of the carby, a normal SU could suffer fuel surge during spirited conering. The HIF44 has the fuel bowl directly underneath it and this is the key (from what I'm told). Webers will not have this fuel surge problem.
My advice would be to order the kit, take the intake pipe to a fabricator with a weber, and say "Make this bit fit this.". Shouldn't be hard or expensive. If you're handy with a welder, do it yourself
If you do get it done, dont forget to take measurments and document it, as I'm sure many others will want to go this path once you've sorted it
Peace
