Ok let me get this straight. You are an enrolled citizen of the Oglala Sioux Tribe (Pine Ridge). You do not currently possess a Sioux war bonnet, likely because you have not yet earned the right to wear one such as by serving in the military or as a recognized leader for your tribe, and no one in your nation has authorized you to do so. You may or may not have applied for your federal permit to posses the needed golden eagle feathers and if so you've probably got a many decade long wait before you could acquire enough feathers to make your war bonnet if authorized to do so.

It has occurred to you nonetheless that it would be a "good idea" for you to wear a warrior or leader's war bonnet for Halloween since you are an enrolled citizen of the Oglala Sioux Tribe.

Presumably you haven't talked to your family members about this. But maybe you have I don't know.

At least, being Oglala, you have an argument for a Lakota plains war bonnet. If you buy one from Bali that is your legal right in the US to do so. Some Navajos on ebay will also sell you one even though they are not a Plains tribe and have no authority to make one.

An actual Oglala traditional maker of war bonnets? Sure they exist. You call up tribal headquarters, or if you're at Pine Ridge, just stop in and ask who that is. They'll give you the contact info and you can talk to that person and explain your plan.

After you do so it would be cool if you would check back here and let us know what they told you.