look at BendTec, Inc
Duluth Minnesota
There are a few good pipe shops with bending capabilities. You most likely will not locate 'shelf' item for sizes you listed (24 & 36 nps).
Once upon a time, I tried to locate a 48" forged ell, finally got a price, only to find out they were figuring a segmented ell made to forged ell dimensions. Make sure what is being quoted.
You might also check with Tulsa Tubebending- I don't know if they go that big, though.