Feather boas are all the rage on push bikes for boys at the moment, so they are selling them in all colours on Pho Hue and Ba Trieu. Drive down one of them, and you can't miss them.

I can't help you with a cigarette holder sorry.

A couple of shops next to Tran Tien plaza facing the Opera, they sell some electronic gadgets and stationary, I have seen long cigarette holders there. Hope they still have them. Good luck !