I think we should support both Stack Overflow (mostly community supported), GitHub (intimate with the code, therefore good for bug reporting/referencing. People are use to and expecting to report bugs here and lookup solutions in GitHub Issues) and IRC (people are going to be looking for help in the IRC either way).
It's not an issue of trying to use a single tool to rule them all. This is simply the nature of the net in it's current state. All of the above provides value in their own ways if the community wants/can support it but the three I mentioned should be our official channels. Internally we can pipe GitHub Issues into another tool to help us better manage issues (zapier: github issue -> trello card for example).