You did not mention your budget.
I think you might want to sell those two parts and look at a more modern setup.
Video editing runs better with lots of ram.
Today, DDR2 ram which the 775 lga typically requires is more expensive than modern ddr3.
To use CUDA graphics capabilities, you may need a nvidia card. Check your apps for requirements there.
A more modern ivy quad will be more effective.
If you persist with lga775, I would look on ebay for a motherboard. They will be very cheap there. If you find one at retail, it will still cost as much as a lga 1055 motherboard. look up the cpu support list of the motherboard to verify that your E4700 is supported. Past that, look for 4 ram slots so you can maximize ram.
Once you have found your motherboard, go to a ram vendor's configurator and see what kits are compatible with your motherboard.