shear capacity can be tough to do with braces alone depending on the size of the structure. and braces tend to work in compression only - unless you have really long tenons (and wide braces and posts or beams to take them). adding hidden or visible steel will work.
what about a moment connection @ the foundation to post? typically a steel shoe that is rigid enough to keep posts from moving about - so braces become a minor part of the overall system?
in addition to seismic you may need to look at wind depending on size and location of the structure. out east (especially on the coast) it will drive many of the decisions.
