I need a head cover .... MTP boonie or cap?
Cut down MTP bush hat for the win I'd say! Takes a bit of crafting, but if you can be bothered:
1) unpick the binding tape around the rim of the hats brim
2) cut 1-2 cm from the outer brim (note DO NOT follow the stitching as a guide - genuine MTP bush hats have the brim stitches as a spiral, so following it with your scissors will end in a spiral peeled apple effect, and no remaining brim!)
3) re-stitch on the binding tape to the outer of the brim to stop it fraying
4) if the hat has too much internal volume, turn it inside out, pinch 1cm of or so of the higher back half of the crown's rim, and stitch it, such that when you turn it back the right way, you have reduced the height of the crown (the rear of the hat is usually higher, hence why you stitch just the back half).
5) place on your head, look awesome, attract ladies.