So I think I may end up doing this:
Battery 12V>Fuse>Relay (on switched 12V)>laptop car adapter>HP laptop>ground
12V Switched>Auto Turn On Module>Laptop Power Button
Battery 12V>Fuse>Opus POL (Dynamix Car adapter)>Dynamix screen>ground
Battery 12V>Fuse>Relay (on switched 12V)>Power Inverter>PS2 (rarely connected)/USB Hub/Whatever else I might need to plug in.
The three circuits will end up on the same fuse block, and then split off to the relay and the Opus and inverter. The screen will probably be wired with the car adapter it came with until I get the POL. The inverter will barely be used, other than to power the USB hub through it's USB port.
Cost:
Car Adapter - $13.99 + $10.95
Auto Turn on Module - $35 + 7.64
Total for now: $67.58, and another $34 plus shipping later for the Opus.