Good day "JM Photography".
Glad to see you got a Mac Pro, I love mine to bits! Back to tacticks.
Question: I take it you want to RAID the two 1TB HDD's for the extra speed when adjusting the photos in PS? This is a good idea, but I'm not 100% sure if the Mac Pro can RAID right out the box? You may have to buy a RAID card? Unless you already have?? And I would do it to if I had the extra cash. But ONLY if you need extra speed. Not sure what you'll be doing with the photos? But if its just for storage, there really is no need to RAID two drives. So you have to ask your self do you need the space or speed?
So if you set that up you would have 1x350GB HDD and 1x500GB HDD RAID. If you do do a RAID 0 you MUST do a back up to another drive, as RAID 0 is not fail safe.
This is how I have my set up (I'm a graphic/ web designer), I have 1 dirve as my boot drive with nothing on it apart from apps and the OS, I have it like this to make the boot faster and seek times, for apps faster. 2nd drive has all my work/ films and music on it. And then one external drive for back up. Now the external drive is connected via SATA, which means I get really fast copying from the two internal drives to the external. Now its not really needed, USB works fine just much slower! And doing the first back up of a 500GB HDD takes ages! Now setting up a eSATA isn't that easy for a neub to Mac person but if you want to have a go?
Macenstein | Review: Newer Technology’s Mac Pro eSATA Extender Cable; The $25 way to add eSATA to your Mac Pro <here, you find what you'll have to do to install eSATA drives (you can have up to two), and
NewerTech® eSATA Extender Cable <here, you can see the cable and prices. And as you can see its a lot lot cheaper than getting a TM (time machine). But if you do want to do this set up you must use ONLY WD (Western Digital) HDD for the external drive, I had a h**l of time getting it to work only to find I needed to us a WD HDD for it to work.
All in all, Get the 1TB internal drive and another for back up, I sould have said you can use another 1TB "Internal" drive as a back up, you don't need it to be external, just me being uber safe.
Hope that helps?
I'll be round here all day if you need help!