It doesn't work that way. Longer nipples are for better access by the wrench on thicker rims, or with washers. Continue reading the book and lots of answers will come. Lots of stuff you probably haven't thought about yet as well. You'll enjoy gaining the info.

The Alpine III are overkill IMO. A well built wheel with 14/15/14 spokes could last you a gazillion years and fifty bazillion miles. Would the Alpine IIIs last longer? Probably. But why? Higher priced, more freight, nipples are extra money, no custom lengths, heavier. For what benefit? A wheel that outlasts your great grandchildren? It's like taking a 3/4 ton pickup truck to the market to pickup a head of lettuce.

You have all the cool tools now. Just build these "normal" wheels with these "normal" rims and "normal" spokes. Get your feet wet in the building. Later....when you want to build a touring bike....build wheels with rims, hubs, and spokes designed for touring.

My 2 cents