Kimio,
If your main concern is concealment, I would recommend an IWB holster. Not as comfy as OWB, but easier to conceal and dress around. With your size I would say pass on the shoulder rig unless you're used to wearing one. They are cool and conceal great under a jacket or coat... but it's almost like carrying a small backpack all day. It can cause back stress and discomfort.
IMHO, it's tough to beat a good IWB or OWB holster worn at approx. 4-5 o'clock with a 15-20 degree forward cant.
Oh... and leather is the only way to go

I'm slightly biased.