The only part that looks potentially erroneous is the 15x200 = 3.0GHz at the end, unless the LV 1.6 Xeons are downwardly multiplier adjustable, which I did not notice in your writeup . . .

Otherwise it looks fantastic - the perfect guide for anyone looking to do processor-intensive work on a budget. If I were into CAD work (like my bro) this is what I'd do, hands down.

Great read!