It's not only not wrong to contact others members about costumes, most of them are only to happy to jump in and help any way they can. Welcome to the gang.
Hehe I do understand about your height and costumes. I have a friend who is like 5'5' and has a star wars darth vader costume as I'm 6' and have a jango fett suit and i look down on him like he is the vader from spaceballs LOL.