I have been searching the internet for anyone to second your opinion, and alas, I cant find anyone. I do, in fact find many people saying that a gaming card will probably not work well for solidworks, and one of the reasons cited is drivers. I guess it's possible that the hardware itself is identical, but that doesnt mean the card will perform the same.
Also, I have yet to find anyone that rates video cards by the number of CUDA cores and nothing else.
Well im glad your google searches are what you are basing your opinion on. Have you considered that nvidia may post 'cease and desist' notices, therefore there are not many posts about it?
I also checked it out, and yes, its not certified (never thought it was) but many people around the traps are using it succcessfully. There are several well know solutions to make a GTX 660, 580, 480, 570 work with Solidworks. But that's not something we can discuss here, but its doable. But that is your responsibility.
ALl I am saying is, don't get sucked into the market hype. Companies that make their money from the number of frames they can render per second, or rely on bullet proof systems, yeah, its worth the money. But they will buy the top end stuff and spend $4K.
Normal everyday users don't need that. Its $200. The architecture is the same. The driver isn't. Its simply a wafer selection process, of which they've created a market.
I thought you'd be better off spending 200 on a Quadro SLI system to double the CUDA cores with similar core speeds to the K600 but slower memory. You can't do it, brand new at least. But if you could find 2 cards, of last gen for $250, and they totalled more than the K600 192CUDA cores, thats what you should do.
Otherwise, just get the 660 GTX, its faster for everything.
CUDA cores and I believe OpenGL perform the processing for 3D. Thats why you use nvidia (quadro). Thus why having nearly 5 times the amount is important. Do some research.
Not confirming it will work, but for the money the 660 is many many times more powerful. For the same price. Period.
I would do some more research if I were you and see if the 660 does what you need it to, prior to buying an overpriced low powered quadro.
Finally, you don't need anywhere near 750W PSU for your system, its low powered and low speced. A quality 500W would suffice perfectly well.