Doable, totally.
I just suggest you do as your future competitors do: outsource production to China.
Let me share my experience with your, since I am undergoing the exact same situation as you.
I have a working prototype of my product, which I drive around with all day. It has a home-made, project-specific Arduino board, with all through-hole components. I also used MDF wood as a "chassi" to the assembly. the product also consists of 10 identical daugherboards, that are connected to the Arduino. Since these are double-sided PCBs, and 10 units, I had them manufactured by iTeadStudio in Hong Kong (total for the 10pcs of double-side 2"x2" boards: $17 shipped to Brazil).
Prototype 2 will have a lot of features over prototype 1, including better enclosude, which will be made in acrylic. It isn't cheap to have acrylic laser cut just for me, but for 1 unit it is great.
If I don't need a 3rd prototype, I'll then just find a manufacturer in China to whom I can send my project files. It is a lot cheaper than having it manufactured in Brazil.
I already filed for a patent for this product, based on Prototype 1, so it is currently "Patent Pending" (or Required). It may take up to 3 years until my patent is granted.
So, my suggestion is: before working on an enclusure, work on prototypes, just so you can test your ideas and concepts, change them, create more, and over the weeks you are using your own product you'll come up with thousands of ideas on how to improve it, and most of them will make the final product.
If you can create more than 1 prototype, have a very trustworthy friend/relative use it as well and give you feedback.