Addict,

1) size A is strong and looks good. Use nylon; silk is more difficult to use and is generally used for bamboo rods.
2) Pre-formed handles are fine and often less expensive, but I've found that gluing up the cork rings on the blank and turning the handle myself does a better job of getting it exactly on center.
3) Most guides are of good to excellent quality. Use the ones you like the best.
4) Epoxy is most popular, but I still use spar varnish (5 coats) because it's a lot easier to remove if I need to make a repair or replace an entire set of guides.
5) Color preserver isn't necessary, but the thread darkens about 4 shades without it. Gold thread becomes brown, for example.
6) A disposable brush for glue or epoxy is needed, or a good bristle brush for varnish. At least one reamer, or rasp, to get corks or handles to fit the blank.

Good luck! It's a lot of fun and can also become addictive. I found myself building rods I didn't need.

Sincerely,

Salmo g.