ZFS over RAID6

[$witch]

hi,

having made a considerable amount of pre-research am now asking your 
mind about my goal.


enviroment :

a FreeBSD (ranging from 6.x to 8.1) web-farm (a couple of links and a 
dozen of devices/servers)


goal :

share (in R/W) some dirs between various hosts via NFS; such dirs must 
be in something that is error-proof.


considerations :

at lower level feel RAID6 meet my requirements (i love something that 
can face a double hw fault)

while at upper level ZFS looks very nice so am looking for such a 
combination.


status :

as now had found some ADPTEC, ARECA and 3WARE adapters that look 
reasonable but controller is not all;
i need also 8 (+ 2 spare) HDs and a case where to keep them.

so had extended research to 8HD cases with RAID6 capabilities.

again a few manufacturer seem to have suitable boxes as

**MGBurly8VRe ( http://www.burlystorage.com/ccp0-prodshow/MGBurly8VRe.html )

and

ARC-5040  ( 
http://www.areca.com.tw/products/esatafirewire800iscsiaoeusb.htm )


questions :

a) do you feel that combination NFS over ZFS over RAID6 a good choice or 
just a complicated exercise leading nowhere?

b) do you feel suitable the listed hw ? [ one | both | none ]

c) do you know something "better" that lead to an overall expense not 
bigger than 2.5 K euro? (had seen some ADAPTEC over 4K euro that seem 
nice but expensive for a test)



thank you



Alessandro