I'm not sure I understand the question. Can you give more details? What sye did you do to the tcase? What rear axle? What yokes/flanges do you have? What yokes/flanges are you wanting to run?
You can make anything you want, just need to find the right combo for what you are doing.
For me, I did the jbconversions super short sye, I put the front output from a 94 np233c in along with a 1350 ubolt style yoke, I'm currently waiting on a 1350 ubolt style yoke for the rear of the tcase, and both axles have a 1350 ubolt style yoke on them. I plan to use 88-94ish k1500 front driveshafts for the slip splines (32 spline), and I ordered 1350 slip yokes for those. I pulled a driveshaft from a wrecked short bus for the driveshaft yokes.
I'd suggest clicking around on dennysdriveshafts and jbconversions to look at yokes and other stuff that's available.
As for you original question about 1 or 2 piece driveshaft, I've been crossing my fingers that my shop will make me a 1 piece shaft, but I know in the back of my mind, they probably won't want to. Worst case scenario, for me, I'll go back to the junkyard and grab some more bus parts and make it 2 piece. I don't want to do that though.