Welcome to the forums, Alexo!
Having two drives would allow you to copy discs "on-the-fly", but since that process doesn't always work well, I'd recommend that you copy from the optical drive to the hard drive, and then copy from the hard drive back to the optical drive. This is how I do it when I make copies of discs.
I have heard that Lite-On drives are good for audio ripping and making copies of copy-protected discs. I can verify that they are good at ripping, but I've never tried to copy a copy-protected disc. Also, Lite-On drives have very good media compatibility, meaning that they will work well with many brands of CD-R and CD-RW media. I have heard that Plextors are good drives, too, but the only Plextor I ever used was a 12x10x32x SCSI drive.
If you want two drives, make sure that your reader is faster than your recorder, or else on-the-fly copying won't work well. Unfortunately, I don't know which readers are good these days.
DVD-ROM drives will generally read CDs just fine, but they are often slower than regular CD-RW drives. Also, DVD burners can generally burn CDs, but again, they are usually slower than CD-RW drives. DVD drives may not handle CD copy protections as well as CD-RW drives.
Unfortunately, I have no experience with any of the Plextor drives that you mentioned, so I can't comment on them.