Highly doubt you can do that, the PS2 doesnt really have anything that resembles Computer components in it. A PC CD Drive wouldnt be able to be hooked up because the cable connections are different, in the Xbox its pretty much having a PC that just plays games, that why you can put in any size hard drive and possibly DVD Drives if you decide to modify the thing
wouldnt mind switching out the Drive in the PS2 myself since it pretty much blows and is so cheaply made, but just dont think you can do that my friend