Am looking for a quality fixed blade knife. Blade of at least 6" up to 8". Single edge ok, better if a partially sharpened upper edge can be ground onto the knife or if it is double edge ok. Quality knife, up to $400. Important must come with a sheath suitable for wearing in urban environment with street clothes, underneath clothing. I cannot send knife into usa to have a custom made sheath. This is the problem. All help much appreciated, thanks.