Be aware: here come some crazed ideads that just float my mind.
The artists probably never wore armor.
This is a big problem iof every animated charackter in every franchise XD
But Bo for instance have some major issues for being drawn to quickly.
Like Filoni stated: Her Role was first set with a male DW-Lt. but then they decided to take a Women for that role.
Thats also the Reason why she had no Face in that Season - There was no time to make a proper one.
The Suit for instance has no clearly visible end at the shoes aswell. So maybe the sole is attached to the skintight strechsuit or the legs extend with an Uber-sized Spat that grabs the whole Boot.
But now for some creative input:
I guess if the custume-wearer has a "perfect" shape like the perfect animated charackter - some grey stretch-fabric like "under Armour" would do it. Who will look on the details of the fabric, when having a good looking A**? ;-)
Another Option: taking a grey Working suit and cut out some long triangles in the length of arm and leg. and then sew them together - but dont forget a zipper or velcro sealing at the end of the sleeves.
The Vest of Bo btw surprised me. because it is NO VEST! It has sleeves! So it is friggin T-shirt! XD
For the fabric i would assume Leather. It may look like its made of grey coal-smuged bricks in the animation (Well everything in TCW has an texture that looks like coal-smudged bricks in the first place XD ) -> but in fabricquestions i rather go with estaded Jango-Standards and say LEATHER. Maybe its just some raw, battelworn leather for Bo?
So i googled for a "T-shirt"+"leather" and well...
http://heycrazy.files.wordpress.com/2010/03/leather-tsirts-elle.jpg?w=600&h=849
there are some trendy leather shirts and tops for girls and I bet there are some grey ones too.
Oh and there are far lot more skintight leathershirts for fetish people and gay ones too.
So if some of you have a problem with that -> you have been warned.
And i take Jango-Standards again. I guess the bottom of the Armorplated Shirt gets just stuffed under the Girthbelt.
btw Girthbelt: Normaly its easy to find a Girthbelt in the right Size in the equitation-equipment for Male's with a stomachal size of 90-110cm and more (its for horse bellys normaly) but while googling it. Short Girthbelts with lentghts of 60-70cm are very rare.
So i would recommend to take a girthbelt with double the size of your stomach. cut them in the middle and make two Belt instead of taking a 90cm long and threw the 20-30cm away XD