laptop for scientific computing

Dear forum members,

I have a question regarding which laptop to buy. I am a long time (since '98) Dell user (Inspiron 5ke and Latitude D 610). In short, my requirements are:

# Heavy number crunching (running large numerical models)

# processing large amounts of data

# visualization (python, tcl/tk, IDL, vis5d)

i.e., scientific computing under GNU/Linux OS.

Of course, desktop would be the best bet... but are there any laptop models optimized for the above? And, are there any benchmarks (performance comparison) available? I wouldn't want to buy anything like the D 610, because I have seen CPU temps beyond 70C for computationally intensive apps (running numerical models). I came across the precision series on DELL's website. But I would like some input before I decide.

Thanks in advance for your time and any help/suggestions!

~rk