Hi, I'm also trying to get Andes to work with international Galaxy s3, I could tell you what has not worked for me:
Stock xxella + boeffla kernel 2.7.1
Stock xxella + siyah kernel 1.8.9
Stock xxellc stock kernel
Stock xxellc + boeffla kernel 2.7.1
I haven't tried with CyanogenMod because it requires a total wipe.