That can certainly be done. Would you want solid brown and solid cream? There are lots of army prints that are available...not sure if you would want that for either the base or the trim.
The coat would be made of exclusively polar fleece, double layer. I use a reinforced stitch, so it lasts longer. Bailey and Emmy wore their's all winter and they held up just fine.
With the measurements you gave me I would say a medium coat would fit just right and cost would be $45. If you would prefer a sherpa lining it would be a bit more.
Kinda like this but with fleece? Totally doable...
