I have been there twice in the Elise, absolutly amazing scenery and the roads were superb. I have driven the roads they did in that top gear special about the best roads in the world (Stelvio is not the best its the road to Obergurgle that is!)
Min you the Stelvio pass looks pretty impressive,
I think this one is better Davos to Bromio
The only thing I know about 4x4ing is that the different countaries have very different (stric) rules so you need a local guide/map that you can trust. LRO did a two month thing on the Hanibal Trail or try klookihng round the web, but make sure you know everything or you may wind up in clink!