The video card in the Sony is quite good for a notebook -- an nVidia GT330M. (My desktop uses a GTX275, which is more powerful, to output to dual 24" monitors but for some reason Photoshop CS5 32-bit doesn't recognize it to use the enhanced abilities, but the Sony does.)
I don't see a problem using the Cintiq on the Sony since the Sony has a DVI port, which is, I believe, what you need. The Sony I bought is standard with 6GB of RAM, but with your layering, if you'd do it on the Cintiq, you might consider an upgrade to 8GB.
I think you'd do yourself a huge favor moving over to Windows 7 x64. I ran Vista (32-bit) for a while, and was generally happy, but the system became slower and slower with each patch and update. Both my desktop and the Sony run Windows 7 x64, and generally boot much quicker and shit down quicker. The added plus is that Win 7 also doesn't generally load a lot of services and processes that it doesn't need immediately. Vista loads EVERYTHING, hence the slow boots.
My 70-200 has been pretty good, but really pales compared to the 85 and 135. Actually, that reminds me, I need to send everything off next week while I have some down time.
Hope the added info helps. Oh, one note regarding adding a USB3 Express card. The Express card slot doesn't have the power to run two USB3 pocket drives, so you have to find a power adapter.