I need some help with the overall shape, I can't exactly figure out if I got the proportions of the body and face right. Something feels off, should I do him a little bit taller , or wider? It's still a work in progress so any advice would be helpful.

It's a little tricky to judge body proportions for a heavily-clothed character, but he looks alright compared to the original illustration. I'd say his hands look bigger in the illustration, so scale up his hands a bit in the model. Also, increase the width of his nose bridge and add more fat to his nostrils so his nose looks more puffed up like the original, and try reducing the space between his eyes as they look little too far apart. It's looking good though. ^^

Thank you, now that you pointed it out I can definitely see those facial features that need to be changed.