Though I know we count several electrical engineers of various stripes and similarly skilled people among our ranks I do have to wonder if we got linked up on some electronics site/forum somewhere.
100+ oz*in
Imperial units in this day and age.... bad form. In real units that would seem to be 0.7061552 Nm (or at least according to
http://www.unitconversion.org/unit_converter/torque.html ).
Judging by your lack of any restrictions other than those posted I assume you just want a dumb DC motor -- no steppers, internal speed controls, reversible/direction change options.... Though hopefully you would not be adverse to having a three pin one (power, ground and go) or something that is not quite the classic two pin motor, if possible I will try to spare you the multi pin or something like a squirrel cage (Kooianker?). I guess it goes without saying as well that you do not want to have to have another motor to start it or bring it up to speed.
"operating at max 12A" It might not come to pass but can I have a starting load as more than that?
The obvious starting point is a parametric search on somewhere like
http://www.digikey.nl/ or
http://nl.rs-online.com/web/
Neither allow for weight in their parametric searches which is annoying. Likewise I have not needed any specific electromechanicals I can not order by part number in some time (everything else I just pull out of my box of salvage and junk) so I have not got any truly good/hidden/only known to those in the trade sources and plugging in various things from your list I did not get far as far as getting your specs at the shaft, though everything roughly appropriate seems to measure its output in mNm or Ncm which is a sign this is going to be fun.
If weight is an issue I guess you do not want to convert it, though
http://www.digikey.nl/product-detail/en/808050X07.66Z/808050X07.66Z-ND/2467164 seems designed to use a gearbox and might just fulfil your requirements (though at 96 grams for the lesser motors the gearbox would probably tip it over the edge on weight, 100 grams is pretty killer though).
http://nl.rs-online.com/web/p/dc-motors/4204997/ does slightly better.
I sense I am wasting both of our times so I will leave it at this for the time being.
