There is another member on here with a write up on a similar system, however mine is different. It uses a properly sized and spaced fan without washers.
I used a flex-a-lite 1519 fan, 851 spacer adapter, 1x 504 spacer (1/2 inch) 1x 516 spacer (2 inch)
Comes out to 119 dollars and free shipping on amazon.
Edit, i just checked the bolts required are 5/16-24 x 3.25 inch, grade 8 torque them to 29 ft-lb dry, or 20 ft-lb with anti seize (i suggest anti seize, also on the 30 mm adapter)
The thing about the spacers is that the outer face of them is tapered, so it self centers the fan perfectly, and they are machined to be balanced, and have a uniform thickness, unlike a common grade 5 washer. They also have a locating dowel in the center. This set up is nearly perfect, this brings the fan blades to exactly one inch from the radiator, the only thing about it is that the fan diameter is slightly larger than ideal.
Hell, i made a amazon list for it
http://www.amazon.com/lm/R2K8GFY4OG8TF0 ... TF8&lm_bb=Please note that you still need to source your own set (quantity 4) of flat washers