Anthony K,
That appears to be a very good choice for your use.
Because that series of Xeon E5 first version are so inexpensive, it is worthwhile to consider an E5-2680 (2.7 /3.5GHz). I think the supply of these will gradually decrease and prices rise over time.
When you receive the system, check the bootblock date and if it is after 6 /2013, it can use Xeon E5-2600 v2. This is worth knowing. The v2 processors will have more cores and higher clock speeds and the system will have a longer future and better value when sold.
It would be fun to know the Passmark test results as received.
My z620 as received:
HP z620 (Original) Xeon E5-1620 (4-core @ 3.6 /3.8GHz) / 8GB (1X 8GB DDR3-1333) / AMD Firepro V5900 (2GB) / Seagate Barracuda 750GB + Samsung 500GB + WD 500GB
[ Passmark System Rating= 2408 / CPU= 8361 / 2D= 846 / 3D = 1613 / Mem =1584 / Disk = 574 ] 7.13.16
And after upgrading:
HP z620 (2012) (Revision 3) 2X Xeon E5-2690 (8-core @ 2.9 / 3.8GHz) / 64GB DDR3-1600 ECC reg) / Quadro K2200 (4GB) + Tesla M2090 (6GB) / HP Z Turbo Drive (256GB) + Seagate Constellation ES.3 (1TB) / 800W > Windows 7 Professional 64-bit > HP 2711x (27" 1980 X 1080)
[ Passmark System Rating= 5675 / CPU= 22625 / 2D= 815 / 3D = 3580 / Mem = 2522 / Disk = 12640 ] 9.25.16
Ausgezeichnet!
Cheers,
BambiBoomZ