XFS filessystem for Datawarehousing

I intend to test Postgres/Bizgres for DWH use. I want to use XFS filesystem to get the best possible performance at FS
level(correct me if I am wrong !).

Is anyone using XFS for storing/retrieving relatively large amount of data (~ 200GB)?

If yes, what about the performance and stability of XFS.
I am especially interested in recommendations about XFS mount options and mkfs.xfs options.
My setup will be roughly this:
1) 4 SCSI HDD , 128GB each,
2) RAID 0 on the four SCSI HDD disks using LVM (software RAID)

There are two other SATA HDD in the server. Server has 2 physical CPUs (XEON at 3 GHz), 4 Logical CPUs, 8 GB RAM, OS
= SLES9 SP3

My questions:
1) Should I place external XFS journal on separate device ?
2) What should be the journal buffer size (logbsize) ?
3) How many journal buffers (logbufs) should I configure ?
4) How many allocations groups (for mkfs.xfs) should I configure
5) Is it wortj settion noatime ?
6) What I/O scheduler(elevators) should I use (massive sequencial reads)
7) What is the ideal stripe unit and width (for a RAID device) ?

I will appreciate any options, suggestions, pointers.

Best Regards.
Milen Kulev