I read that you can use ultraiso to shrink images (stupid easy too), but apparently you need specific older versions (versions which were never specified -_-")
So i tried it with my version, which happend to be the newest. The game i used was BLACK (false LBA). It boots fine, first level plays ok, not sure about the rest though.
Anyways, i like to use ultraiso, its much easier. But i figure....there must be a reason why everyone else uses isobuster and cdgenPS2. What's so bad about UltraISO? Did i just get lucky with my test subject?