But wouldn't that technically be a modpack then?
Modpacks are always going to have problems. The FTB team are simply amazing at what they do, but it's very, very difficult to get multiple mods from multiple authors to play nicely, and there would (theoretically, ok) be far less of that in this situation.
And then there's the update situation to consider too.
Mod packs are comprised of mods coded by different people. With different techniques/ programing styles.
But a bunch of different mods, even a very large number of them, re-coded by the same guy or group of guys should have far less problems.