Well, running 7 of then would be nearly 9dBA higher than just 1 (regardless of which fan you choose, it'd be 9dBA higher). So 7 SLs will sound like 1 SH (or there abouts). This is past my tolerance for noise...but some people can take it (and then some).

7 SHs would sound loud...lol.

As for whether or not you want to put them on a fan controller, or in what groupings (I don't know of a fan controller that can do 7 individual channels). Again, that's up to you. I think fan controllers are great since your system won't be at full load 24/7 (unless you crunch and have no GPU....and in that case 7 fans may be excessive anyway, lol), so why keep your fans a full speed 24/7.