Hey Los.
I hate to say this, but considering you need a stealth model you may want to give the X2 by Smokeless Image a second look. I just got mine in the mail, and with an iGo carto from NHaler I don't notice any difference between this and the Echo. And there's no LED except when charging.
It is a little longer though, because of the pass-
through charging function, but the weight between my 900 mAh X2 and the 650 Echo is negligible. the X2 is a bit more expensive though.
Hope you're doing well.