Hardware for ZIL/SLOG to improve sync-write

[daimi]

I went through most of the url posted jgreco,
http://forums.freenas.org/threads/some-insights-into-slog-zil-with-zfs-on-freenas.13633/
http://forums.freenas.org/threads/s...xi-nfs-so-slow-and-why-is-iscsi-faster.12506/
http://forums.freenas.org/threads/nfs-performance-with-vmware-mega-bad.12240/page-2#post-58089
http://forums.freenas.org/threads/bbu-hw-raid-only-for-zil-slog.14925/
http://forums.freenas.org/threads/nfs-performance-with-vmware-mega-bad.12240/page-2#post-58089
http://forums.servethehome.com/raid-controllers-host-bus-adapters/1517-hba-cache-bbu-2.html


-- Initial setup --
i) ESXi running from USB
ii) FreeNAS VM (as vmdk1) will be stored under local datastore (created through SSD connect to onboard AHCI controller)
iii) FreeNAS VM (with pass through M1050 flashed IT mode and connected with HDD) will create a zpool_vm, and then NFS share to ESXi for hosting the rest of VMs

-- Question --
In order to improve sync-write:

Q1) How about putting FreeNAS VM (as vmdk1) + ZIL/SLOG (as vmdk2) under the same **local datastore**

Q2) The **local datastore** in Q1 should connect to what device:-
a) onbaord AHCI controller (same as initial assumption)
b) M1050 flashed IT mode
c) RAID with BBU
d) PCIe Flash Drives (Acard device, ZeusRAM, DDRDrive, or FusionIO?)
... what else?

Q3) The **local datastore** in Q1 should used the drive of:-
~ Type : HDD?/SSD?/supercap SSD?/SLC SSD?
~ Size : 7.5GB? = 3.5 GB (zil memory -> to be half of 7GB FreeNAS memory -> 6GB baseline + 1GB/1TB storage) + 4GB (FreeNAS install)

I am looking for a $500 solution to fix the slow sync-write problem,