I have a mobile setup consisting in a saffire 56 + octopre and if I need more channels I add an Audient ASP008 going into Toshiba Laptop, now I´ve upgraded to a Vaio
From my experience:
- XP Optimized with a partition ONLY for audio, no internet no shit
- Fast HD, 7200 rpm minimum for recording separate from OS
- Dual core minimum
- 2gb RAM minimum
- Fireware port with Texas Instruments chip if possible
- Graphic interface not integrated in the motherboard
That´s what I´d search for, and that´s what has worked for me, luck!