Recreating the Blue Paul would be quite a challenge for you but could also be a very rewarding experience. However, you have to do it just right and document everything. To do something like this requires some knowledge of genetics (or partnership with some who knows genetics) to be able to understand the results of certain crosses.  There are several articles and a big forum post on here about coat color genetics which may help you understand the coloring gene. So if you are serious about doing this and doing it right you can't just throw the dogs in the yard and wait for pups. It must be planned, researched, and documented.  If you have a well thought out and documented plan you may have better luck finding stock. Also, consider importing your foundation dogs as many US breeders are totally opposed to anyone crossing "their" dogs.

So:

• Make a plan and clearly document what you are trying to achieve
• Designate your foundation stock and source them from supportive breeders - establish baseline genetics
• Plan your breeding
• Test for structure, temperament, color and drive
• Cull
• Check you plan - did you achieve what you want?
• Document and evaluate results
• Find a good time to introduce new stock to the gene pool and fine tune your desired results.
• Document, document, document, test, test, test, but always - maintain a disciplined approach.

Good luck.