Building legs without barbell?

Basically I want to get some more meat on my legs. I have read the few leg hypertrophy programs in "Beyond Bodybuilding" and a few other books, but all of them are based on barbell squats. Now i dont have a barbell, but i train only with kettlebells. So I was wondering if front squats with one or two kettlebells, or overhead squats could replace the barbell squats? Are heavy barbell squats the only way to build legs, or can it be done with high volumes of front etc. squats with a moderate size kettlebell ?
Thanks ahead for your replies.