Im a singer first, then guitarist 2nd (actually i shouldnt be callin myself a guitarist  :<>)

So I never want a guitar to over take my voice, but I love singing powerful acoustic stuff, I like to be delicate, but I think I will always need that ability to strum hard and aggressive (on those climatic moments of the song).

Seems L-series can do this....does the D and L differ that much?

Also, besides larrivees what other guitars do you believe are great for singers?

All guitars can be great for singing. It really is more dependant on your style of playing and type of music. I use both a D-03 and a Taylor 714ce to play while singing. The D-03 is my big strummer, and my Taylor is for fingerpicking and light strumming. From your description, I'd go with an L body style.

Are you talking singing/playing acoustic or plugged-in?  If plugged in, I say size does not matter, it's amplified, so go for the comfort of a smaller guitar like an OM.