Hi Smoogle,
Welcome to Insights!
Based what I read in the net the H1Z1 game will run if you have this PC requirements based on Planetside 2 game;

For Intel users with Nvidia GPU:

• Core i5-661 3.33 GHz
• NVidia GeForce GTX 560

For AMD users

• Phenom II X4 910
• Radeon HD 6870

These are the recommended requirements but what about the minimum requirements?

For Intel users with Nvidia GPU:

• Core 2 Duo E6850 3.0 GHz
• Nvidia GeForce 8600 GTS 512MB

For AMD users

• Phenom II X2 555 Black Edition
• Radeon HD 4850

Therefore a R9 280 will run fine based on your system specifications.
In regards to the other two ports you mentioned, those are Mini DisplayPort outputs. The Displayport output has the same benefits as HDMI as it can transfer video and sound but has a higher bandwidth as you can run resolutions up to 4096×2160 at 60Hz. 
If you plan to add a third display that is not DisplayPort capable, then you have to use an active adapter on those ports to make the proper conversion to whatever connector you want to use. If you want to add a fourth display you need to do the same.
The R9 280 is capable to run up to 6 displays but you need to use a MST Hub.

If you have further questions please post here.

Regards

Thanks for the quick response paul! Do you mind telling me what are the differences between this Club R9 280 and the Club R9 280x?

Hi Smoogle,
The main difference between both GPUs are as follows;
R9 280X VS R9 280
Effective memory clock speed: 6,000Mhz vs 5000, 20% higher memory clock
Floating-point performance: 3,482 GFLOPS vs 2,964 GFLOPS, 15% better floating point performance
Clock Speed: 1,000Mhz vs 960Mhz, 4% higher clock speed
Memory clock speed: 1,500 vs 1,250Mhz, 20% higher memory clock speed

Thanks again paul once last question how will it be able to handle a game like Witcher 3? I am thinking about streaming the game so dual monitors plus running witcher 3 will it have to be on medium or lower? does it even match the requirements well?

 

Hi Smoggle,
I am not sure what monitors you have and what resolutions you plan playing.
At 1080p you should be fine with your system.

yeah I’ll be playing on 1080p  I heard that AMD processor is super hot so i guess i need good cooling,  there was news on DX12 today

DirectX 12 is coming to all Fermi, Kepler, and Maxwell GPUs  – does that apply to this card as well im not sure which one the r9 280 is

Hi Smoogle,
DX12 is supported, you can find more information under specs here