I own a 5hp Delta spindle shaper and 3 wheel comatic feeder (Amazon deals). I look for crazy new/newer/brand new old stock equipment for crazy prices and have succeeded in building my crazy hobby shop for less than the 15 JR spindles as well pretty much.
The Delta HD shapers have removable spindles as well but no where near as nice as pneumatic ones. They do however can serve a similar function (and cost 1/3-1/4 as much). Here is the 1 1/4" one. You can install and remove the spindles without changing the height. This way the spindles are all at the same height thus preserving your setup. There is another threaded rod that threads into the bottom of this spinle. The spindle shown slides into the bearing/drive assembly and is keyed to fit. That secondary rod that is threaded into the shown spindle is then fitted with a nut on the bottom end of the drive assembly.
I so wish there was some way to own JR's two shapers he has for sale. I look at them and just drool. $170 each for a hobby shop is just crazy!
Another dream I have is that Laguna Panel Master shaper system. It is even more at $15K! It is a multi cutter system that has all the cutters for a door already mounted. The heights change, the fence changes, and you are ready for the next cut. The table is a X/Y precision glide system. It is nuts.
Using the multi shaper Weaver door system will change you as well. My mentor's shop has these and he pumps out multiple doors in literally minutes! Those setup with the belt fed feeders are a sight to see.
Glad its my shop I am responsible for - I only have to make me happy.