What sould I look for ?
 

If i wanna buy a cd writer what ''spécification'' should i look for ?

Don't buy the first fast writer you see.
If you gonna buy a new writer make sure you get one that is capable of perfect EFM coding (two sheep on Olli's writer list). This will not be advertised on the box so you need to have prior knowledge before you shop.

I would recommend a Lite-on 24X, 32X, or 40X (or 48X if it's out?)
or even take a look at what LG's have two sheep.


Besides that you will want a writer that is at least 24X, 2Mb buffer is minimum, buffer underrun technology is a must, I can't think of other stuff right now.