I would think that 2000 cfm would be enough for your combo. But is there any in that size that move more air? If not then you may want to look into a fan shroud of some sort. More air is never a bad thing when it comes to engine bay heat. Anything you can do to get it out of there and keep the engine as cool as possible under normal conditions. Do you have AC in the car? That will put a lot of extra load on things while it is running.
The Painless relay shoud be just fine. Be sure it is rated correctly for the fans requirements.
