I would go for a DVD Writer, best thing i did for a long time was to purchase 1. Alot of games are coming out for the xbox that are simply 2 big 2 rip to cd-rw, u can always get the multiple cd rips (Not 2 keen on em), but u are still stuck with a small set of rip releases. If u have the money like u say u have then its money well spent.
An example of a cd-rw rip that springs to mind is spyhunter. the rip had 3gb of movies ripped out, thats alot of shit to rip.
obviously there are down sides the dvd's aswell. Metal gear solid is about 6gb so it wont fit on a dvdr so ur screwed there 2.
My suggestion to make sure u r as future proof as can be is to get a dvd writer and a large HD cos even if the game is over 4.3gb the release groups always make a multi dvdr version that can be dumped on to the xbox HD.
U can use %99.9 of general dvd-r media and 2 be honest it seems to work better than the dvd-rw even at 2x.