I have a LaCie DVD rewritable drive. It has a firewire (400) and USB 2.0 ports. It can write DVD-RW, DVD+RW, 4xDVD-R and 4xDVD-R. I know that jaguar does not support all of these formats. i believe that Panther supports a few more. I have use Apple DVD-R and Imation DVD-R with no problems. I just use the slowest burn speed to reduce problems.
I have a couple of Fuji DVD+R and a DVD+RW, that I have not tried yet.
iDVD want an internal drive, and need 1.2GB of disk space. I don't have the space right now. I need to alter may partitions. I was able to get iDVD off of the DVD, but due to space limitations I could not load it.