It does looks like you are specifying some really heavy duty hardware. The disks normally are the bottleneck. Because you are striping the rule the more spindles the better. SSD is much faster but I have had no direct experience with it. NetPerfMon can not be split between machines.
One more note - I did find some references to write SSD times being slower than disks. If this is the case you don't want to go to SSD. The manufacturers demo reads and call it fast read/write but they don't directly demo writes.
My opinion would be to forget the SSDs and get as many 73GB 15k drives as you can. It sounds like you need more spindles as Andy mentioned above.