Fwiw I am getting a few khaya blanks with my next wood order. I looked around for cherry but nothing yet. You can get walnut necks from Dave Maize (at least he has it listed) or octopus. Port orford cedar from LMI and a few other small dealers I can't recall right now.
From what I read on khaya, it can range from really light, coarse, with internal tension to nice, dense and darker in color. I think it is wise (with all wood) to slice a thin piece off the blank's side and see if it twists badly. I've found a few Spanish cedar blanks with lots of tension which I had to turn into dentellones.
Same with spruce. Once I split 5 blanks for the transverse braces but didn't get a chance to finish and glue the 2 for the soundboard. Next morning they were really badly twisted!