Personally if it was me I would get the 120w just to be on the safe side.

That's why I was looking for 2 150W to make sure that I have enough power to drive that sucker. One thing it is worry me is 630mA and I am getting a 700mA driver.

If the old one is 630mA & you go with the 700mA your good to go. As it is you don't use 700mA with the old drivers.

The 96w drivers are comparable to the drivers that are in your fixture right now. You can go up to 120w but as Eli said you do risk over driving the LEDs. Those drivers in your fixture according to the specs of 130V max and 630mA are capable of a maximum output of 81.9watts each. I'm not sure where they are getting the 300watts from but most likely that is just the theoretical maximum that the LEDs can run at.

I would suggest you try to find out what kind of LEDs are in there. From that you can get the Maximum Current and Forward Voltage to find out exactly what drivers would work. Doing it any other way you risk frying the LEDs which is why I would recommend going with a lower driver.

Should you pump 240 watts into the fixture with 2 drivers the LEDs might be capable of that but the fixture might not be capable of dispersing the heat.

Did you try contacting the manufacturer for their input?