Thanks for the info you'd found on chaps. My husband and I are avid riders and I've been experimenting with chap making. I've made chaps with anything from 3oz to 5oz leather. My tendancy would be to stay with a 5oz leather for everyday chaps that will take a beating but the 3oz upholstery leather works nicely for show style chaps.
As far as riding in chaps...I currently ride in full length, zippered shotgun chap made of about 4 oz suede leather. (I didn't make these) I love the full length chaps for cooler days and tough trails. They've saved my legs many times from branches and brush. And along with a full length oiled jacket, I am toasty warm while riding in the rain or cold. Summers are not so great since they get super hot to ride in. So I'm in the process of making myself a nice pair of chinks for summertime riding.