Zaiten: I picked Sailormoon because she is my favorite. Her personality, her bubbliness, the way she believes in the goodness of people, how she refuses to give up on love. :) I was into voice acting a lot when I was younger and my favorite character to voice was always Sailormoon for that reason. I have wanted to make Seramyu ESM for probably like 12-14 years now so... it was an easy decision for me when I finally grew up enough to be able to afford doing it the way I wanted to. ;)
I would have to agree with choosing the one you identify with most. Otherwise you're investing a lot of time and money in someone you won't enjoy portraying!
Panda: I used craft foam and covered with gold foil spandex, and used my nail to etch the lines in it. :)