How to set up my 'blog' area to look and work like the WPMU DEV Community?

I removed all the ‘blog’ pages from my Wiki site as they were causing me grief when changing themes, trying different options, etc.

I need to get my blog set up and would like it to look and run like the WPMU DEV Community pages do, but with my categories. Is there a plugin for this or a theme that WON’T overwrite the theme for my wiki?

And, is there a way to copy all my 80+ wiki categories to the blog or do I have to manually enter all the categories?

Mary :o)