It might be a help to set out exactly which aspect(s) of quality are important for your needs, and ask the various suppliers if their products will meet your needs*. This will allow you
a) to sort out those firms who really know about the stuff they are selling;
b) to rely on what they say as part of your contract when you buy – not fit for purpose is much easier to prove if you have clearly stated your purpose.
c) to let us know how you get on …
* this might include the hardness, the dimensions of the taper, the provision (or not) of centres in both ends, the relation of the taper to the blank diameter, the concentricity of any draw-bar threads, etc – just depending on how wear resistant, accurate or interchangeable (etc) you need them to be.
Cheers, Tim