For your first use of silk (assuming you've had even a little experience with size A nylon) I'd recommend you go to Anglers Workshop http://www.anglersworkshop.com/items.aspx?catid=2871 and pick from their good selection of 3/0 silk. AW branded thread appears to be identical to YLI 3/0, a relatively easy to use thread highly regarded in bamboo and high-end custom glass and graphite rod-making circles. It's significantly thinner than size A nylon, but somewhat thicker than Pearsall's Gossamer. Silk isn't as hard to use as some would have you think, but it will catch and fray on rough fingernails, callouses, etc, it doesn't stretch at all, so you've got to be careful how much tension you put on it, and your guide feet should be thinned down to a knife edge on the end and be filed very smooth. Depending on your age, you may need good lighting and optical help to ensure smooth and even wraps. Color preserver is only needed if you want the color to be the same as it is dry. Otherwise, finish as you ordinarily would, with varnish, epoxy, urethane, Perma-gloss, or Lumi-seal. Since the thread is thinner, you don't need high-build finish, and your wraps will look better with thinner finish, anyway. A little practice is recommended before tackling your "dream" rod.
CC