Can I get my book formatted before my cover is designed?

Yes!

We only require your cover if you have ordered EPUB files, since we insert the your cover into one of the two EPUB files you receive. This is because some publishers require that the cover is inserted into the EPUB in order to publish with them. If your cover is not ready yet, we can always insert it into the EPUB file once it is finished.

For all the other publishers, you will upload your cover file separately when you publish and the publisher will insert the cover into your ebook at this time.