I have a navy blue wool flannel blazer that I'm looking to enhance by changing the buttons. I'm trying to decide between horn or smoked MOP buttons. This is my first time doing this, so I'm not very well versed on buttons. Should the buttons be shank buttons or will thick buttons work for this blazer? (does a smoked MOP shank button even exist?) Where should I go to purchase these buttons? Any other suggestions? Thanks for any help.