Attic "Bonus Room" Insulation

Hey gang, I've decided to go with metal studs because my niece can get me a good deal through her company, which will include the drywall as well. In fact, they will deliver everything down into my basement! So this is a no-brainer for me - I have to use the metal studs because I can't pass up on the savings. Anyway, here are some questions I'd like to have answered: 1. What thickness/guage metal studs are best, or most popular to work with and why? Oh, I needs screws also - type? 2. What's the best way to attach the bottom seal plate to the floor? Glue them down or use concrete nails? 3. Is it easier to build your wall on the ground first, or is it better to attach your bottom and top plate, then add the studs? 4. How important is a vapor barrier when I have half (exposed) the basement walls already insulated by the builder? Only the top half of the walls are above ground level. 5. If I need a vapor barrier, what kind of plastic should I get, what thickness? How is it applied? Do I cover the whole backside of the metal wall I am building? I know I have quite a few questions so if someone could recommend a good book instead that would be great. I want to finish my basement right the first time. :) Thanks![B]

I need to put a railing down to my basement. How many fastners do I need? Would it be every stud,every other stud? Is there a code for this. Wall is drywall with studs on 16" centers.