I'm a big fan of sleep! I hope it works for you. While I have/have had some wonderful betas in my time, I'm not big on collaborative writing. To me, it seems a very personal thing to do. I might ask someone I trust if what I'm planning makes sense, or expect them to call me on it if/when it doesn't, but that would be the extent of discussing a fic. I respect your having had a good experience and missing that back and forth, but if you've done it before by yourself, you can probably do it again. Try the sleep thing!