I may be able to offer a fitted version.... no opening in back. (though they are around $20 or so if I remember correctly) I'll post a JPEG with style and color options as soon as I can.
A fitted hat normally costs around that amount, so that's seriously NOT an issue, if you were thinking that it was. For something custom and related to this for us, I'm of the opinion that $30 wouldn't be out of line. Naturally, I wouldn't WANT to pay that much, and would DEFINITELY like it to be more in the $20 range, but I just wanted you to know your price point there isn't outrageous.
If I may throw my opinion in here, I think it would look better if it were set up like the Nike hats (and others) currently out there. Although they don't have a web address on the back, the placement of a third embroidery element I believe would look sharper on the SIDE (the BYOAC), and have the URL follow the curved opening in the back.
For a visual example of what I mean, here you go:


For the URL, you have it down pat from the last hat.
As an aside, something like this should never be made for BYOAC:

and lastly, I'll take one in khaki or navy....haven't quite decided what color, only know that I want one.