We're currently using Shurley English 2. My two dd's hate it, BUT it gets the job done! Maybe I'll switch next year to MCT, not sure (but it appears that a lot of replies here are in favor of it). Shurley does not diagram sentences, it parses them. Also, with Shurley English you do get some composition in, so you do not need to add that.
We also use Spell to Write and Read (SWR), which is very similar to Writing Road to Reading and Logic of English. SWR would be less expensive than LOE, as it's a one time buy, and can be used for ALL grades. It is Not open and go, and is very teacher intensive, but well worth the effort. SWR encourages students learning to write Cursive First - which is a program that can be implemented separate from SWR, but goes specifically with SWR. SWR is considered an intense phonics instruction program. It does incorporate composition and grammar, but does not exist for that purpose.
We tried Serl's Language Lessons, but my dd's were not into it at all, they like the strict stucture of Shurley English better (even though they fight it). Serl's is more of a Charlotte Mason approach as well as the Queen Homeschooling Language Lessons.
I have a sister who swears by CLE Language Arts as it is COMPREHENSIVE - you need nothing else to supplement - that alone may be a big plus. I looked at it, but didn't really like how it was set up. (I do like their math though.)
HTH