Yes, you can get it here:
I know it looks like an order form thing but it's really free and you only have to fill out the first page. They will only send you one e-mail containing the CD key.
And don't be shy to try the 64 bit operating system. Just make sure all the drivers you want are compatible. Because you see the 64 bit windows will run any 32 bit program without any loss of performance. But it needs to have 64 bit drivers for all your hardware.
I know ATI has 64 bit beta video card drivers, not sure about nvidia but they probably have them too. I know that there are also 64 bit drivers for some RAID devices and for a lot of motherboard devices. But just make sure to search on the net and check to see if every piece of hardware you want to use has 64 bit drivers available. Otherwise it won't work.
If all your hardware in compatible than I would recommend getting the 64 bit windows.
Only thing that stopped me from installing it was a linksys wireless pci card. That was the only component I could not find drivers for.