i'd say the best place for a blog forum, if it goes ahead, would be within the Webmaster Help section.
As for the default template....you can modify the default template very much so in the admin panel in case you're worried about lossing out on mods compatability with templates. This is the default template that is used here with a few CSS modifications
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Changed the borders to blue, narrowed the forum to allow for a background, modified the logo on the top.
Although it wouldn't be wise to narrow this forum in my opinion as you rely on your banner space for adverts and the like...