Hi there im doing a gaige cosplay as well ive had a few prototypes since November
For her belt, I would suggest getting a utility belt at a hard ware store that should be good and pretty accurate.
Her arm im still working at my first prototype sucked, then i tried making it out of foam and it worked pretty well after i painted it with silver rubb n buff but i feel like i still need to find a better material.
For her hair ties i held them up with regular hair ties and i actually but the pipe holders from home depo and put those on top works very well
basically i suggest going to a home depot and getting a lot of nuts and bults you could also make it out of foam and do a good paint job
if youd like to see how thoose turned out email me at firstname.lastname@example.org
and ill gladly sent you pictures of the specifics and how it worked for me