Sounds like Zoe is your best bet, since you have most everything for it. If you try to cosplay anyone else it can get pretty expensive not only trying to buy the rest of your costume items, but conveying them all to your dressing room. I have a fake mare's leg you might maybe make use of. ;)

SARIS!! Why didn't I think of that?? They shouldn't be that hard to sew. Basically, they're big rectangles of cloth, and I can custom size it b/c I'm so short. Thanks, stinkingrose!

I highly recommend saris.
; )

I'm tall and fit the Zoe body type best and I've assembled most of a Zoe costume myself.

Brown and khaki stretch pants from WalMart of all places. They are so comfy that I've bought them in several colors and they go good with my brown boots.

This Halloween I bought a kids rifle from one of the costume stores and fashioned a holster out of cardboard and brown leather like vinyl fabric paired with a Zoe like belt from Target.

Zoe's necklace is from Jetflair's jewelry collection and I'm looking for the right vest and top.

I most likely won't wear it at Dragon Con though. I'm a resident of the South and knoe about the heat! Just my Firefly/Serenity/KNTR tshirts.

Hi PhyreLight. This summer will be my third visit to D*C and I will be marching with the 76th in Saturday's parade there. Honestly, I understand your concern about the heat/humidity but most of the con takes place inside air-conditioned hotels so the only time you have to be in the heat is darting between the three venues so wear whatever you want! Actually the only time I wore the full costume was for the parade and my volunteer stint at the SEBC's table and I was not uncomfortable at all! My friend wore a River costume which was basically a slip dress and big black boots and she was very cool and comfortable the whole time. Lots of us in the 76th also just wore jeans and Firefly or Serenity tees as well. Hope to see you there in whatever you choose.