What are the benefits of a 64bit OS? Really? Why do you need to address more than 4 gig of memory on a computer that runs a CNC controller? Sure, the hardware is 64bit, but just because it's 64bit doesn't mean you have/need to use it.
Here is an analogy: I have a 800 HP engine in a 67 Camaro. But do I use that 800 HP to go to the grocery store? No. I use my 185 HP grocery getter.
If you want to use the PP, do option #1. You have your Mac to play on.
But I would do option #2. Just add $159 to your $400 PC and you will be very happy. Make that leap and I promise you that you will never want a PP again.
Option #3 (the VM stuff) is not going to work. I run VMs for a lot of things in my day job. And I can promise you that this option is heading down the wrong road. The host OS has dominion over the guest OSes. So even if the PP driver did work, it would not work correctly as it would not be the hos OS that it is running on! Expect really crappy timings if it even works.
I would be doing Option #4 along with Option #2. Just for the fun of it! (Been thinking of getting one of those Arduinos for myself)
Seriously guys, 64bit Windows PCs are really only needed for insane things.
If you run multiple VMs for development purposes, you might need a 64bit OS.
If you calculate PI to the x trillionth precision, you might need a 64bit OS.
If you run a 3D modeler with thousands of parts on an assembly, you might need a 64bit OS.
If you have a word document that is larger than 4 Gig, you might need a 64bit OS. (only possible with Office 2010 as that is the first version of Office that is native 64bit!!!!)
My question to all is this: Did you find yourself needing a 64bit OS last year? Or the year before that? Or the day before you 32bit PC died? Where you said to yourself "Damn, if only I had a 64bit OS I could conquer the world!"
Steve