Since I really just want to tone up a bit and lose weight, I'd be happy to be doing less weight and more reps.
Given these goals, and the fact that you have herniated discs there's no reason to ever squat heavy again, in fact you don't need to squat period. Since you injured yourself doing a deadlift type move, you should probably avoid deadlifting too. There's so many ways to train the lower body without barbell squatting and deadlifting. Work around your injury. A lot of professional bodybuilders never squat or deadlift. People online can be really elitist about powerlifting movements, and I've been guilty of this before too, nothing is more satisfying than chasing numbers and lifting heavy to me, but don't believe this propoganda. Also don't fall for the "perfect form = never get injured" myth.
So squat and deadlift if you can, but for people with chronic injuries you can get a great body sticking to safer movements too.