Buying Mbox Pro and iMac

Hey folks. I will purchasing an Mbox Pro and a new iMac to run the system this week. I've been checking the compatibility pages to see which of the new iMacs have been qualified. It appears that the only 27" inch "Haswell" iMac that is qualified is the i7 3.5GHz. Anybody here using the 27" Haswell 3.2GHz i5 successfully with Mbox Pro and PT11? I want the 27" iMac, but I don't want to spend $2700 for one! I can get a closeout 2012 "Ivy Bridge" 3.2GHz 27" iMac for $1350 that is qualified with Mbox Pro and PT 11, but I cringe at buying a computer that is nearly 2 years behind the technology curve. Plus, the compatibility page doesn't specify if all versions of PT 11 will work with the "Ivy Bridge" iMacs (and OS 10.9).



Also, is it still recommended to use a dedicated separate hard drive for ProTools files? If so, I still have an OWC 7200 rpm (FW400 and USB 2.0) that might be usable.



I purchased an Mbox2 back in 2004 that I used for several years. Before that I worked as a staff engineer using a top of the line TDM system (late 90's, early 00's). But I've been out of the loop for awhile now and the technology has made quantum leaps. Forgive me if I ask ignorant questions...



Thanks!