There are some definite weight loss with coil overs up front. Double adjustables either end are a good idea for max tuning ability, but not mandatory. I'm running Afco BNC coil overs up front, just putting Afco doubles on the back this winter (previously had stock mount Qa1 doubles on the back).
One issue up front is if the car needs travel to hook properly as well as how much stored spring energy is needed to help transfer weight. The more power you have, the less travel you need to plant the tire. My car has 1050 hp at the flywheel and it needs at least 3" of travel to hook properly, but that is on a 295 drag radial tire. I know Eric Kenward's TRZ wagon uses 1 1/2" travel on a bad track, zero on a tight track.
It all comes down to the combination.
Why do you think you want coil overs?