Yes, I have looked at your set up and it's a real nice setup. I've learned quite a bit by your photo's....thank you for posting them.
I am going to be using nema 23 steppers in the range of 305oz/in unipolar//425oz/in bipolar and probably a spindle big enough for aluminum, but mainly for wood projects using the aspire software.
Glad my photos were of help to you. I have a question, please don't take this the wrong way but why do you feel the need to use such powerful stepper motors? The Shapeoko 2 frame was never designed for such beefy things, even if you do reinforce it in similar fashion to what I did to my machine. I fear you'll also snap the belting relatively quickly if you're goal is to have super fast rapids and feed rates with high levels of torque. Personally I would not go above NEMA 23s that are in the 276oz - 286oz range for the Shapeoko 2, though you might be able to get away with using the 305oz/in unipolar that you mentioned. My machine has NEMA 23's rated at 166oz and they're plenty powerful for the Shapeoko 2. I can have rapids in the 400 IPM range if I choose to and so far my experience with cutting acrylic and aluminum have been able to give adequate feed-rates.
What router or spindle do you plan on using? Just like the stepper motors there is such a thing as going too big and too powerful. I would recommend that you don't go beyond the 1HP range. An 800w spindle (1HP) weighs 5 pounds and that's considered really heavy for the Shapeoko 2, even if reinforced. That's the most powerful spindle that I would recommend. If you're going with a router instead the Dewalt DWP611 is an ok choice too but not at the same level as a spindle.
Now I'm going to side step real quick. Any reasonable and logical person would think that a 1.25HP router would be the better choice when pit against a 1HP spindle, I mean who doesn't want more power? However even though the Dewalt DWP611 is advertised at 1.25HP you're not going to get that. Consumer tools don't follow the same standards as industrial tools. A spindle is an industrial device and is rated using the international standard RMS (root mean square) power. This standard is accurate and verified prior to labeling the tool.
A router, as a handheld consumer device can be advertised using peak horsepower. This means the designers can use perfect voltage, perfect temps, and tweak any other parameter to develop a theoretical horsepower rating, even if it's only a burst of a few seconds, and market the tool rated as such. Some people may try to call BS but a 1HP spindle will actually perform at a similar level as a 2.25 HP consumer router, such as the Porter Cable 892 or Bosch 1617EVS for example. Few if any 110v consumer routers can actually produce and sustain 1HP, regardless of what they're advertised to produce. A good rule of thumb when it comes to consumer routers is to take the peak HP rating and cut it in half, that's more or less the actual sustained HP that it'll give you.
I'm assuming you'll want to work with hard woods and aluminum? I would recommend a 1HP AC spindle if you have the money. It's leaps and bounds better than a router when it comes to CNC machines.
Here's an an example of what can be done with four 166oz stepper motors and a 600w (3/4HP) DC spindle. I managed to cut some new spindle mounts for my 800w (1HP) AC spindle out of a 1/2" thick aluminum plate. I designed them to be compatible with the stock Shapeoko 2 mounting plate. Here's a couple of photos of that.