Yeah. Using the disk drive for a combination PS1/GameCube portable would be *Can'tSayThisOnTV*ing hard. Not impossible, but let me give you an idea of the difficulty.
The drive interfaces are completely incompatible with each other. The XBOX 360 DVD drive uses a Serial ATA interface. The GameCube is proprietary, and I believe the PS1 has the drive controller right on the motherboard. You would need to engineer a disc drive emulator for GameCube and another for the PS1. This is not impossible. The Wiikey Fusion can do the former. I don't know of anything that does that latter. This is some seriously involved flax. You would need to find documentation on the interface or reverse-engineer it, then build not one but two drive emulators from the ground up. I'm talking about FPGAs and really complex programming here. Of course, there is also the other half, reading data from the XBOX 360 DVD drive. That is a more normal interface, but that doesn't mean it will be easy. I'm thinking you'll need a buffer of some sort for this scheme to work, but I'm not sure. That's right, I don't know, and judging by your spelling and grammar, I'm a Heck of a lot smarter than you.
I don't even recommend the 360 laptop until you do some research and get some practice.