Buying a new coat -- questions about Merino and Toscana sheepskin

Hello,

I found the style forum when looking for a women's coat to replace my 7-year old down parka. Hope you guys don't mind me asking questions here! 

I am in central NJ.  A parka is usually warm enough for the winter. So I thought about just getting another parka, and actually found one (please see the link below) that might work well. It has a cotton shell, so it probably won't make as much noise as my current parka. The color is practical too.

Shield Coat, by Andrew Marc:

http://www.andrewmarc.com/womens/shop-andrew-marc/outerwear/shield.html

But then, I learned that there is something called "sheepskin", and started to think maybe I should get  a sheepskin coat instead, one that's casual-looking, at knee or thigh length. From what I read, Merino sheepskin and Toscana sheepskin seem to be the best (i.e. lightweight, warm, soft, etc). So I spent weeks looking for coats in such materials, and found two I like:

Toscana Lamskin Duffle Coat, by Nursey of Bungay: 

http://www.nurseysheepskin.co.uk/catalogue/product/1004/3005

Merino Spring Lamb Shearling Coat, by Mill Valley Leather:

http://www.millvalleyleather.com/All-Sizes-Available-Traditional-Toggle-in-Ultra-Fine-Merino-Spring-Lamb-Shearling-Skins-with-Fine-Buffed-Suede-Leather-Side-Dark-Chocolate_p_81.html

Before I pull any trigger, I'd like to check with you experts -- is either Merino or Toscana sheepskin is going to be too warm to wear in NJ?  Is one more durable than the other?  Also, which one do you think will be more suitable for casual wear to work? No one at work wears formal clothes, not even dress shirts or dress shoes. For outwear, I have seen my co-workers (mostly guys) wear down-filled parka, wool duffle coat, wool pea coat, leather jacket, etc. 

Any comments or suggestions are welcome!  I appreciate your input.  Btw, I am petite (5'2''), if that matters.