Hi @hiroshi, the floor and seams can be either black or the same colour as the tubes – it is your choice. The product page tells you how to indicate which style you prefer.
I recommend a Large packraft for your stature.
The kit does not include a printed manual, as all of the instructions are on the How-To web pages, including pictures and videos. I answer questions quickly, and whenever someone asks a question that is not already answered on the website, I update the site so everyone else can find the answer as well.
Cheers!