Well, you're golden then for equipment.
I'd do the following:
Server1: Fast Storage
14 Samsung SSD: Storage Array, Raidz2 (with SSD, you don't need the increase reads from raid10)
1 Samsung SSD Hot Spare
1 Crucial SSD - Zil log
USB Raid1 for OS
Server 2 : Slower Storage
12 2TB RAID10
2 Samsung SSD for L2Arch Cache
1 Crucial for Zil
USB for OS
With that setup, put the machines that need the speed on server1, put ones that don't need as much speed on server2, and have fun.
I'd do the following:
Server1: Fast Storage
14 Samsung SSD: Storage Array, Raidz2 (with SSD, you don't need the increase reads from raid10)
1 Samsung SSD Hot Spare
1 Crucial SSD - Zil log
USB Raid1 for OS
Server 2 : Slower Storage
12 2TB RAID10
2 Samsung SSD for L2Arch Cache
1 Crucial for Zil
USB for OS
With that setup, put the machines that need the speed on server1, put ones that don't need as much speed on server2, and have fun.