Are you talking about a playing on stage sound or a recorded at home/studio sound?
If it's the former I'd love to know too but as you gave me advice in a previous thread about amplifying an acoustic live I would guess not.
Is there an example of the sound you want to get to that you could point us at?
From the little I know about this and have found out good acoustic guitar sounds are based on nice sounding guitar - mic positioning - stereo recording - and particularly good quality mics. A friend I do some things with has a big guitar electronics sound which is loud and to my ears horrible but each to their own
Big fat sound suggests things like compression - doubling the track - perhaps a touch of chorus - multiple parts - other instrument fattening the sound. Not sure about sexy or how you do that (is it like slinky? LOL).
My son gets a nice acoustic sound - shall I send you or post somewhere some examples of the sorts of sounds we get from what is an INCREDIBLY primitive set up at home and you could at least go - "god those are horrible?" :)
One of favourite acoustic guitar sounds is on an album from donkeys years ago by Elton John on Come Down in Time. There are about two bars where I just think the sound is just lovely - it sounds like a beautifully played acoustic.
I also have a Pat Metheney solo guitar album which has a nice sound (on a baritone guitar I think).