Aloha Steve.
Here is an additional approach to consider.
If you are going to be using Cubase, why not use what Steiny recommends?
Made for each other: Cubase and HP
Finest software requires finest hardware. That’s why our best software specialists rely on the world’s leading PC hardware manufacturer. Cubase 7 is quality-tested with HP’s professional Z series workstation computers, ensuring highest performance and maximum reliability packed in a rock-solid chassis. Carefully selected components optimized for recording, editing and mixing allow for efficient audio data transfer rates throughout the whole system. Be it the industry-proven Intel XEON processors or the ultra-fast SSD drives, HP Z machines squeeze the best out of Cubase, speeding up your entire studio software environment.
From the site:
http://www.steinberg.net/en/products/cubase/whats_new/whats_new_in_cubase_7.html
Good Luck!
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