It might simpler and not much more expensive to simply replace you HD and DVD with their lower power laptop counterparts. These typically use only the 5V rail instead of both the 12V and 5V. The M1 will more than handle everything you mentioned in that case.
If you must keep the desktop components, another alternative to using two supplies is to replace the M1 with one of the other supplies that has slightly more capability on the 12V rail. The Opus 90W, 150W, or a Carnetix + PWxx solution would work for you.
If you really want to run multiple supplies, you probably don't need a solution to to power your HD, DVD and LCD. The M1 should easily do one if not two of those at the same time. If you can get the HD and DVD to work on the M1, then powering your screen with a simple linear regulator based circuit would work -- perhaps with dimming or power cycling during crank. You could also sample a TI 12V switcher module (search the forums) to handle the screen.