I would like some idea about a good workflow for Website Design, with a high degree of "offshoring" (Elance, Odesk etc.).

I would to do as much as possible "pre production", with client input, ideas etc. stored in IA diagrams, wireframe mockups etc. in something like a Wiki.

Also a like the idea about having different people come up with different design proposals.

Wouldlike to have some ideas of costs of different phases and tasks ($, %, hours).

With Design I mean roughly the aspects of a site that can be done with client-side tools, especially XHTML and CSS.

What other tools should I use than IA diagrams.