I've sprayed my case and the drives, meaning... I've done the case sides, top, face, and the feet on it. This is the Inwin full tower. I've also done the drives. I've done my floppy, ide zip drive, pioneer slot-loading dvd drive, as well as my plextor 8x4x32 ide cdrw drive.
Things to consider.
To cut your case, you might consider a drill to cut yourself a hole. Then use a saw and cut away. Remember to take your time. Some cases are tougher than others depending on the material and build quality. I also have a Dremel and it takes a lot longer with it. You may want to use a Dremel after you've completed cutting to sand the edges and basically clean up your cuts.
For the plexiglass, I went to Home Depot here in California. They carry plexiglass and Lexan. I went with lexan because it's tougher, has a more solid feel. Given that, it cost about 22 bucks for a piece about the size of my full tower side panel.
For painting your drives, again, take your time. You'll want to paint it in layers, as you should, and let it dry each time. Don't do as someone said above and just paint the drive. You have to remove the plastic face from the drive and paint that. Remember to use tape and cover up whatever you don't want painted. I also applied a glossy finish on my stuff. It depends on what you want.
If you have questions, or want pictures, email or message me via AIM or ICQ.