Wow, 1000 rpm, now this is spinning. I once chucked up a long piece of 3/4 inch stainless solid round into the lathe and cranked it up to 700 rpm to get a super smooth finish. Anyway I was just starting to get the lathe wound up when the solid round whipped around so much that I thought the thing was going to hand grenade on me. Now I am much more timid on speeds over 360 rpm. (Of course for long pieces I could always go get the hydraulic steady rest, but that is crazy talk right there)
As for the high speed steel, or carbide inserts, I am not sure which one would work better. Cocobola is pretty hard wood so I assumed carbide would work better. We have had good luck with Veletine solid Carbide Inserts with a radius for cutting stainless steel, a metal that tears more then shears. I have used it on plastic (delrin) and it does work, but a bear to get a nice finish on. How well it works on wood is yet to be determined.
The approach angle will be 95º if I use carbide, but only 90º if I use a a high speed steel blank. I suppose I could grind my own cutting edges to a different angle if the approach angle would make a huge difference, or adjust the tool holder in relation to the centerline of the spindle? The problem with that is, you would have to offset the tail stock off of centerline to cut a straight cut along the axis of the spindle. Not a big deal, but it would involve a bunch of guess work.
Maybe by the time I am all done, I would just be better off chucking this wood up into my Craftsman lathe, as crappy as it is, and making my spindles on that? The problem with that lathe is, it does not have a four jaw chuck, nor does it allow stock to put pushed through the headstock, which together kind of limits what I can do on it. Oh that and it only has three speeds. It doesn't have a carriage either which means I would actually have to do something while the machine spins. I guess I got used to making set-ups, then pulling the carriage feed quill and watching the machine do all the work for the next twenty minutes.