I have a stock ROM in an Odin flashable format and I don't think it's that hard to convert it to a format that works in TWRP or CWM. I don't want to upload it because it's really big but it's pretty easy to extract from Kies.
If you do a complete firmware reinstall from Kies (I did it by starting an emergency firmware recovery) then it will open a window with a loading indicator that takes a really long time. It takes a long time because it is downloading the stock ROM. If you look in your system temp folder while this is happening (try "cd %temp%" in a console window if you're not sure where that is) you'll see that there is a file with some randomly generated name in the root of the temp directory that keeps growing to over a gigabyte (just sort by size and it will be the file that keeps getting bigger and bigger). The file it's downloading is the ROM in an encrypted form. If you wait until it finishes downloading then it will decrypt the file as the same name but with .zip extension. As soon as the zip file appears you need to quickly copy it to another location before Kies deletes it. Now you have a stock ROM!
The hardest part of this whole process is actually getting kies to start the emergency recovery. I read that you can just do it from the tools menu but for me it did not work until I tried flashing something in Download mode and then intentionally yanked out the usb cable while it was downloading. This essential soft-bricks the device and puts it into emergency recovery mode which allows you to download the stock ROM via Kies.