Generally, for off-road driving, you want a "driving" light.
"Spot" lights or pencil beams, are for high speed driving, to give ultra-long distance visibility. Fog lights gives a wide spread of light, but only a super-short distance in front of the vehicle, and are made to keep glare down, both so they can be used on the road and so they don't cause glare off of fog to the driver.
Driving lights are the in-between, with a beam that goes pretty far and pretty wide, depending on the lamp. Bigger lamps will make a wider beam, and generally will go farther.
Best bet is to just get a set of quality brand name lamps you like that will fit. Something like the Hella 500 lamps might fit the bill.