I found you via the Mighty Summit :)

Good luck with your move to WordPress - I love it, but I'm biased, I work for Automattic (WordPress.com) :) I have about 9 sites all running WP, some on .com and some self-hosted.

As for plugins, to be honest, it doesn't need a lot of extra things. I suggest Super Cache which will help serve your site faster, but don't worry about getting the "best" plugins - you can find those when you really need them. Most of the SEO plugins are overkill, I don't use any.

Good luck! :) I'm @rosso on Twitter.
