Suggestion for hardware for ZFS fileserver

[Sami Halabi]

Hi,
I'm planning on building a machine for fileserver using ZFS (still
considering vanilla FreeBSD VS FreeNAS).

I would like to get recommendation for good and working hardware.
I have 2 setups I'm interested in getting your help for each.
1. Heavy load machine with 10G connection.
2. Light machine with 1G connection.

Both setups will have up to 22 SAS hard drives 2T each + 2 SSD for L2ARC.
For both setups I would appreciate your help in:
1. For raidz2 best strip of vdevs for maximum capacity with reasonable
performance.
2. Hardware recommendations in terms of:
CPU
MEMORY
HBA
Sas expander for future connecting Jbod
Server (aka my own build VS brand one like HP/Dell.. Etc).

Thanks in advance,
Sami