I can't help you with the waraji ... can't remember a single Anime North Bleach cosplayer having them on -__- there was hoards of them this year! The tabi’s are easy(er) if you get a pair of white ankle high nylon socks (got my at a dollar store but they were women’s) cut a line down to split the toes and sew on the inside no ones going to tell the difference since “modern ones” are completely solid (no stitches)
If your compelled enough to have a pair of waraji you can use a cheap straw sandal (I wish I had a picture) one size to small, cover the edge (usually black) with straw or twain(easier to find) and build up a mesh like the ebay picture or even better from the actual drawings from Bleach.
I've heard (but never actually looked into it) that waraji are easy to make...
personally I'm too bloody lazy for that...but if you've got big feet (like me: 31cm boats) it can be tough buying waraji big enough.
My pair I kept after a samurai battle re-enactment (living in Jpn is a bonus) though I hear that Cospa sells them.
Tabi too...I think.