Hi Duncan and WELCOME!

In answer to your questions, I am not familiar with the company or the quality of the work, but I can tell you that the Polyviscose is very good material, and I have several Kilts made with that material and find them very sturdy and comfortable.

In regards to your second question it is entirely up to you. I have both solid and tartan, and no one really says anything bad about either, but then again, I am not known for being a small guy.

Just a thought so take it for what it is worth, if you are having qualms about what others may say about a solid not being a Kilt, I would probably select the tartan. Again just my thoughts.