Nope, the new G4's use a "4x" SuperDrive...straight from Apple's Site:
SuperDrive (DVD-R/CD-RW); writes DVD-R discs at 4x speed, reads DVDs at 8x speed, writes CD-R discs at 16x speed, writes CD-RW discs at 8x speed, reads CDs at 32
And that mic you already have would probably work, regardless, your best option is to TRY it before you buy a new one.