If you are fixing this to a wall with drywall on it, you will need 2 1/2" long finish nails to toenail it with, at the tongue edge. If you are staining it, DO NOT face nail it. If you are painting it, well nail it anywhere you please. The wood you are planning to use will work very well, make sure it will give you the look you want by making a sample, say 3' square and place it so it will take on the light that come from windows, lights, what have you. This is done at the wall you are planning to cover. The surrounding colors of the painted wall or stained cabinets that are nearby will play into the choice too.
The saw you linked to is a good saw, maybe more than what you need to do the job, It is made for heavier material but it will still cut small trim pieces too. I have used another brand that was made like this and it cut very small pieces too. It will serve you well for many years to come if you get it. Be mindful of its cut capacity, it looks like it has a capacity if 5 3/4" at the 90 degree setting, it will be much shorter on the 45 degree setting. If you are making all square cuts, no problem. I would consider getting an 8" slide compound saw, larger capacity, lightweight. I have an old Hitachi 8" compound slide, I have owned for the past 15 years, worked it to death, replaced the armature once, the brushes twice, did it myself, still doing a great job. Here is a link to the modern replacement of what I have been using