I'm partial to the Qoob myself When I was researching chips I decided that the Qoob was better then the Viper but it's been so long at this point I forget exactly what my reasoning was
The Qoob comes in the two flavors.. the Qoob SX and the Qoob Pro the pro is more expensive and has more features, morst notably a larger onboard bios that will allow you to store small applications right on the chip like Action replay or an app to rip games to your PC. I believe it can also play MP3s
the Qoob SX is just your bare-bones chip. if all you want to do is play backups this is the one you'll want. This is the one I ended up getting but after seeing some of the cool stuff I could have done with a Pro I wished I spent the extra $$ for that one.
You'll also want a Broad Band adapter because you wont be able to rip games without one... also with a BBA you can STREAM applications to the GC which is very useful.
As for getting a bigger case... I personally perfer just buying the mini-dvds they're only slightly more expensive then normal blanks but worth it IMO... you can get them at
http://www.meritline.com/ritek-mini-dvd-r-media-4x.htmlIf you go with those make sure you burner is compatable with that media... if it's not you'll just burn coasters.... the GC is VERY picky with it's media so you'll want to pick good media and use a good burner. I perfer the above linked media with a compatabile NEC burner. That combination I've been able to mod over 12 GCs and I've never ONCE got a DRE and never once had to pot-tweak.