The Cheap Place has a whole boatload of embroidered patches for members of the military. Among them is the US Marine Circle patch found in the Military Patches section of the website. It's a bit unusual in the sense that it is mostly white with gold lettering and trim. You might not find this one as attractive as some of the others, but it has a unique classiness and elegance that I think is pretty cool.
The style of this patch dictates it probably should be worn on a dress shirt or jacket rather than a leather vest or casual shirt. Even so, you can mount it anywhere you want. If fabric is your choice, it has a heat activated backing with glue that should adhere to most things other than leather and vinyl. For those two materials you'll have to use needle and thread. If you want to mount it to a block for display purposes, a couple of jabs at glue will do the trick.
Remember that all of the military patches at The Cheap Place are available as wholesale patches for resellers. The Cheap Place promises never to knowingly compete with you directly on sites like eBay, so you won't have to worry about them selling to you and then trying to undercut you at the same time. If you're interested in wholesale patches simply open up an account with The Cheap Place and you're on your way. It's quick and easy.