apples or oranges? First off, eibach makes several different types of springs, some of which might be what you're looking for, some of which certainly aren't. Second, there are other good springs out there too. Third, there are other good coilovers out there as well... I'm not quite sure how you narrowed it down to those two choices, but both are reputable products.

If you want to be able to adjust your ride hight, you'll want coilovers. Both Skunk 2 and Ground Control do the trick for a reasonable price. If you're looking for a super-comfy ride, coilovers might not be right for you (or indeed, many lowering springs)... in that case something like Eibach Pro-kit or H&R OE sport springs might be better.

You'll have to elaborate on what you want out of the springs before we can give you a straight answer.