MacPro (Late 2013) - Headless resolutions

Hello all !

I have just received a MacPro for use as a workflow, pdf and photo processing machine. It will be using automation software and runs headless as it sits in our Server/Comms Centre in another building and I get to it using Apple Remote Desktop.

Now seeing I have spent so much money on it (about $5K in AU) I would have hoped that the headless resolutions would at least be similar to the previous Xserves doing the job currenly. I can get upto 1680 x 1050 on both of the Xserves ... Screen realestate is very handy when you're building workflows that fill any screen!

Looking at my options so far on the mac pro I only see 1024 x 768 and 1280 x 1024 ... Seeing this box is running 2 AMD FirePro D300 GPU's which I believe can run upto 6 monitors... I would have thought Id have the grunt for at least 1 more screen res in headless mode !

Anyone know if there's a knack to this like on previous Xserves where a dongle was need to fool a Graphics card into thinking it had a larger monitor on it ?

Thanks for any advice or input !

Regards

Mitch