I’d recommend the latest version for virtualbox.org. Unfortunately, last time I checked, the OSS version of VBox (which is included with openSUSE) has limited USB support; so your best chance of success is with the proprietary version (a free download for personal use). The version directly from Sun has usually been a few version behind in my experience.
Google’ing “virtualbox iphone sync” brings up a large number of hopeful hits; looks like some people definitely have got it working. Most of the guides are for Ubuntu (duh), but most of the tips should be fairly consistent (just don’t try following “howto” instructions for Ubuntu on openSUSE…).
If I see anything that looks more definitive I’ll post here again.