If you got 12gigs of ram you could either use a ramdrive and boost system speed or just rely on windows caching in all the data from the drive.
Most SSD's aren't that much faster than good S-ATA drives in sequential read. In gaming you may have faster load times but mostly everything is cached in the VRAM and RAM so yeah.
Of course it's nice if browsers and other software open up fast but with a small SSD you will run into trouble once it starts to fill up.
I'd recommend aiming for 120gigs or you will probably have to compromise. You can, for example, put the pagefile into a ramdrive or the users directory on the data drive (your 1TB disk) but well, if you can spend the money, sure, go for an SSD. If you really need to save money and can't afford the 120 I'd recommend to wait until they get a bit cheaper. 64gb is really a bit small. I'd consider 80 as the minimum.
But that's just my personal experience of course.
