You may want to check out the Incase sleeve. I have it for my iPad 1 and I think it's one of the best I've encountered.
The incase sleeve looks awesome! but it's too expensive for me
Crown case suede sleeve on amazon. Is $12. I love it.
ordered a colcasac sleeve that says it'll fit with the smart cover. haven't received it yet (it's backordered) but i haven't heard anything regarding the status nor have they responded to my email.
Found out the one I ordered is back order too. They finally responded to my e-mail.
I ended up ordering this one off Amazon. There is a video up on YouTube. Looks like a nice fit.
http://www.amazon.com/gp/product/B0...&pf_rd_t=101&pf_rd_p=470938811&pf_rd_i=507846