Advise on buying used mac pro

Hello folks,

I am just currently a PC user but I would like to move to the mac world. I am interested in a desktop mainly for my photography. I mainly use Lightroom 5 and Photoshop from time to time but not a lot since Lightroom introduced the brush. I wanted to check if anyone has any experience with Mac Pro and Nikon D800 files.

The Mac Pro I was considering is this. Is this going to be fast enough? If not I think I might just go for the new iMac.

http://eshop.macsales.com/item/Apple/MB871LLA16S2/

Thanks!
Dimitris

Hmm seems to work for me. Its this machine from OWC

Apple Mac Pro
2.66GHz 4-Core Intel Xeon Processor
MB871LL/A (Early 2009)
Compatible with / Ready for Apple OS 10.9 Mavericks
Used | Very Good Condition
OWC Tested. Quality You Can Trust.
OWC individually inspects and fully tests every pre-owned computer to confirm full functionality and accurate grading. All refurbishments and/or upgrades are performed by our Apple Certified Technicians. That's why OWC is the most trusted name in Mac refurbishments.

System Configuration:
Memory: 16GB (4x4GB) PC8500 1066MHZ DDR3
Storage:
1.0TB 7200RPM HDD
240GB OWC Mercury EXTREME Pro 6G SSD
Optical Drive: 8X Dual-Layer SuperDrive
Networking:
Built-in Gigabit Ethernet 10/100/1000BT
Video:
NVIDIA GeForce GT 120
One Mini DisplayPort, One DVI Port
Pre-Loaded/Licensed Software:
Pre-loaded with Apple OS X 10.6.8 (Now supported by Apple for up to OS 10.9.x 'Mavericks')
Apple iLife

This is the attraction to me as well. I can put a couple of drives in and enjoy backups for my photos in one box. I was just wondering if anyone had any experience with regards to the speed of this machine and Lightroom 5.