Alternative X and graphic drivers. HOWTO ?

[Bob Alexander <bob@ngi.it>]

I have this Thinkpad T40 with a fairly standard Debian sid on it.

Reading some appends it appears that using the X.org and/or ATI's binary 
driver could enhance performance and/or stability (upon 
susupend/resumes) of my machine.

Do  I understand correctly that I can run EITHER XFree86.dfsg OR X.org 
on my machine and that Debian packages for the latter do not exist ?

Any HOWTOs on how to transition from my current state to the other 
without breaking (too much) stuff ?

Take care,
bob