See this
round up in another thread.
It seriously depends on the budget and what type of editing your girlfriend does.
My favorite (on paper, I haven't actually tested it) is Dell T7600: starts at about $4-5K for a decent configuration that's suitable for Premiere Pro. An HP Z820 costs about the same. For $8K-12K, a well configured T7600 or HP Z820 may get into the
top 50 PPBM5 results.
If you need someone to customize and configure it for you, yours truly will be happy to.
That said, you can get a very decent non-major-brand system for under $3K - as long as it's properly configured for Premiere Pro purposes. ADK and Puget Systems are two known integrators specializing in just such systems.
Alex Gerulaitis
Systems Integrator
DV411 - Los Angeles, CA