Pre-built Linux workstation vendors

[Janicki at ia-inc.com (Chris Janicki)]

I'm looking to buy a nice Linux workstation for software (Java) 
development.  I'm still new to Linux (but not Unix) so I just want to 
buy a pre-built, pre-configured, pre-compatibility-checked system from a 
decent vendor.  (I've built my own PCs before, but I just don't have 
time for those headaches again.  :-(   The only curveball is that I'd 
prefer a dual head (two monitors) display capability, if supported on Linux.

Any vendor suggestions or warnings?  

Thanks,
Chris

PS:  I have a spare Sun Ultra- 5 here... anyone interested at a fair 
(Ebay-comparable) price?