Advice requested for these products and any suggestions; Links below

[JAZZCNC]

I hear what you say regarding the PC and interruptions etc, Ideally I would love the MACH3 on my Macbook Pro under parallels (emulation or virtual PC) using the USB and assigning it all resources when running, but I need to see what others are doing, and if they are being successful

Yep I hear you but Emulation is a None starter I'm afraid with Mach3 so don't waste your time trying and looking.!!

Reason it's a None starter is because of pulse timings.?. . Emulation doesn't and can't provide accurate enough pulse timings no matter how many resources you throw at it. To be honest even the parallel port under windows struggles and the ONLY reason it works with Mach3 is because of the trickery of the parallel port driver. Which is basicly a Virus inside windows which takes over the system and rules the roost.

So you see the parallel port driver which is the heart of the system won't work inside emulation.
Regards USB then even if using Windows PC you can't run Parallel port thru USB using a converter etc. Again due to timings and how critical pulse timing works. The ONLY way you can use USB is with a device like the UC100 which is a hardware & software device.
The only way you can get your Macbook to work is with an external motion control device like the Uc100 etc.

Please take my word on this to save your self some serious stress and time by not even going down this route.

My first choice and strong advise is to buy an external Motion control and Ethernet based one not USB as Ethernet is so much better. There really is no comparison to parallel port and you'll have much more stable machine that performs like a rocket.

Second and only other choice is stand alone PC with 5V parallel port, not 3V. It's very important the voltage coming out of parallel port is 5V or very close to it. 3V is not good enough but unfortunatly they are common on newer PC's.
Reason 3V isn't good is because of the Logic state falsely switching.? CNC machine works by Digital ON/OFF or HIGH/LOW signals and these work by 0v to 2.5v = Low and 3v to 5V= HIGH.
With 3V PP there isn't enough difference between HI-LOW and any electrical noise floating around will cause havoc with signals and switching it's state falsely causing all sorts of havoc and air pulling.!!

Think of the Motion control side like the human heart.? If your heart doesn't pump correctly then no matter how good the rest of the body it simply won't perform like it should.!
The parallel port is like the heart of some one who eats well enough but smokes 40 a-day and doesn't exercise. It will get you by day to day but try to run too fast and you'll struggle badly. Try to Run a marathon without training and you'll likely die.!!

Ethernet Motion control card is like fitness fanatic who looks after him self and runs marathon every day.!!

Edit: Just to Add IMO the Parallel port is dieing Technology so best avoided. Like wise USB is unstable for timing critical devises so again best avoided. Ethernet is designed for high speed pulse signals and perfect at it even over distance.