Hi, I am making an xbox laptop, here is my blog where you can see my progress: http://seb3.yolasite.com/sebs-blog.php
It is harder than I thaught It would be but I encourage you for starting to build one.
Make sure you sort out some proper cooling as you dont want overheating.
You can use my idea if you want.
Follow ben hecks 3 part tutorial on engaget(I am doing this)(google it).
Make sure you can buy/get hold of all the parts you need before you start.
Hope this small bit of advice helped you,
and finally GOOD LUCK
(you will need it), it's a hard thing to build and xbox laptop.
Hope it goes well and if you want I can give you extra advice/ information and meybe we can exchange ideas(just a thaught)
Bye for now.....