The concept of speed from a platter drive is obsolete. If you compare the speeds of the SSD to the two HDDs in discussion, you will see there is relatively no difference in speed between the two HDDs. The SSD is far faster than either.
So save money on the HDD and put it where it will do the most good... a bigger SSD.
On the RAM, just realize that using it at what they have rated it for is considered an overclock of the CPU. That's where the memory controller is.
So buy protection:http://click.intel.com/tuningplan/