The 8 piece Cap.

[BellyTank]

The ones from the usual on-line hat stores are surely OK- if they had a leather sweatband installed. The proportions look OK.
They're around 12" diameter 8 panel construction-

B
T

 

[SHARPETOYS]

I ordered 2 with your size specs from B! Wear.

 

[IndianaGuybrush]

Awesome Sharpy, be sure to post pics as soon as they come in.