My first, and formost advice would be
stay the goddamn hell away from Monster Cable.why, you ask? isn't Monster Cable supposed to be "the shit" ?
well you see, Monster Cable has, of late become a group of slaves to the dollar. they have made it their mission to slap anyone who uses the word "Monster" with a lawsuit, claiming copyright infringement. it doesn't matter if they win or lose, they're still incurring massive legal fees on the part of the respondent party. this includes
http://www.monster.com, the place you go to look for jobs, and
http://ww.monstervintage.com, a place that sells vintage clothing - hardly someone who is going to steal cable-manufacturing business from Monster Cable.
Aside from unbridled corporate greed, Monster Cable is also guilty of selling overpriced garbage to the Best Buy crowd. i'm not sure if there is a more articulate way of saying it but...
your video quality will not magically improve just because you pissed away $75 on a set of Monster Cables considering the video output produced by the Xbox is not the be-all and end-all of widescreen gameplay. My advice to you would be to buy a High Def AV pack and get whatever cheapo or medium-priced component video cables you can, provided they are long enough. also - no matter how much some asshat will try to tell you, there is really no different in sound quality between a $20 Toslink optical audio connector and one that would run you $120...although the $120 one probably looks cooler, and for that difference in price, it damn well better wash your dishes and make your bed too.
My own setup involves a Mad Catz combination PS2/Xbox component video set....it has Y, Pb, Pr and regular old analog audio(connected to my beat up late 70's Marantz stereo rig) and it cost all of $20 canadian - and it smokes. don't get sucked up into the hype - you'll cry about it later when you realise you wasted your cash.