Hmm… Perhaps if you went to a second hand clothing store you might find a jacket close enough to the style that you could have dyed blue. In any case, you probably want some sort of headband nder the hood to keep it from blowing off or something unless its made to fit your head just right. Slikscreening is the way to go for the logo, you just have to provide them with a good picture of it.
Maybe email these guys.
Purple 9 Productions wrote and produced a show called Cobra: The Musical and toured it around to different Fringe Festivals. It was absolutely hilarious!
They might be willing to reveal some of their tips and tricks.
As for the logo, if you have a semi-decent printer, I would suggest getting some of this iron-on transfer paper and try to steal a cobra logo from some website. Ive got an $80 Epson C62 Inkjet and I find this stuff works great. You should see some of the t-shirts I’ve made!