Make Mail more like Gmail

I'm trying to get Mail to work more like Gmail. So, I use the threaded format in my mailboxes. However, is there a way to get the Inbox to display both sent and received messages so that I can get a real threaded look? I can do this with other custom mailboxes, but I can't use any of them as my "Inbox" and get it to function exactly the same. Is there a plugin that can do this if Mail can't by default? So, any help is appreciated!