Component sizing help!

Stock size lines will work just fine. I'm going by memory here, I think they are all 3/16" lines.
You most likely will need a 7/8" or 15/16" master cylinder, if you are not running power brakes. I ended up with a 7/8" Baer m/c. Works fantastic with the standard-size Stainless Steel Brakes Co. (SSBC) disc kits on all four wheels. That size m/c is O.K. to use with one or two-piston calipers. Not sure if it would be big enough for 6-piston calipers or something else exotic... but it doesn't sound like those are in your plans.