hashcat 3.10 Ubuntu 12.04 different GPUs HD5830, HD5970 - what driver works for both?

Hi,
I am fairly new to this.
I currently have a GPU rig running nicely with:

ubuntu server 12.04 LTS with Gnome
hashcat version 3.10
(4) ATi Sapphire Radeon HD5830

I was never able to get any of a multitude of radeon drivers to succesfully install but whatever comes with Ubuntu 12.04 seems to work for the
HD5830 cards.

I also have a
ATI Radeon HD 5970 2GB GDDR5 Graphics Card (DW5CW)

I have tried aticonfig --initial=all -f   (might not be quite right - not infront of machine at moment)
the command works,

but the 5970 is still not recognized even after a reboot.
Card is powered up but I can not interface with it at all.


I am assuming this is because it is newer it will need a special driver.
Note: It is not recognized even if I disconnect the other HD5830 cards.

Does anyone know what driver I should use and will it work with the HD5830 cards I already have?

I went to the ati site and used the driver selector, I forget which driver i attempted to install but it was the recommended driver.
It did not install correctly.
The log file says it is missing a file, it recommends and apt-get command, it doesn't work.

I dont have access to the  error message at the moment, I will post it later.

In Summary - These Questions:
1) Can i use two types of cards at same time e.g. (4) HD5830 and (1) HD5979?
2) What is the best driver to use?