If you don't wanna break the bank you could look for a pie of Corcoran boots such as these http://www.amazon.com/Corcoran-Jump-Boot-M-Mens-Boot/dp/B008M22830
You could start with some jump boots like these, and modify them.
https://www.amazon.com/Corcoran-Jump-Boot-M-Mens-Boot/dp/B008M22830
these are good alternatives. they're american military parachute boots from ww2 I believe, don't take my word on it.
Love the simplicity of your fit, looks like something vince staples would wear.