To use ide-scsi you definitely need scsi support. You don't have to enable "scsi cd-rom support" however, since that is for real scsi drives. You can also leave out "ide cdrom support".
It's not a bad thing to enable scsi support at all, since it is also necessary for e.g. usb flash sticks, usb harddrives etc. etc.
It appears that in the 2.6 kernel series there is also a new driver for atapi cd drives which addresses the drives directly -- i.e. not going through the scsi layer at all. However I can't tell you much about that, haven't tried it yet. ide-scsi works fine, I even drive a dvd+-rw through it.
Indeed the drive will show up as a scsi drive: /dev/srX or /dev/scdX (depending on distro) instead of /dev/hdX.