No one has asked a few of the important questions here yet so I'll do it:
What are you hoping / intending to use the shaper for and have you ever used one before?
Do you realize that you will likely spend more than the cost of the machine (even at ~$5k) eventually in tooling if you buy quality, new tooling in order to be versatile and flexible?
Not saying this to deter you, but your goals matter in terms of recommendations of a light duty 3-5 HP Taiwanese / Chinese machine compared to a 6+ HP mid-heavy duty machine (that is likely 3 phase.)
I would buy none of the 3 you listed in the OP and look for something used Euro, 3 Phase, 6HP +, 1 1/4" spindle and manual controls for half of ~$5k and buy a VFD for well under $500 and be done with it and have a machine much better than the new ones you linked to.
The problem with the lighter duty machines, aside from being *lighter duty* motors, spindle, quills, weight/mass, etc etc is that often times the fences suck and nobody wants to use a shaper with a fence that sucks.
Also HP of the motor is not the critical part of a shaper, IMO. It is nice to have plenty of HP but the other parts of the machine are more critical to me than motor size. That being said, I do not complain about the power and smoothness of the 12 hp spindle motor on my Wadkin shaper, but I didn't buy it based on motor HP.
You should pick up a copy of this book below and study it, watch the Roy Sutton videos on YT (even though they are old, they are still quite good for safety and fundamentals) and definitely pick up a decent power feeder if you are doing more than pattern work.
https://www.abebooks.com/servlet/Boo...RoCnCQQAvD_BwE