If you're only going to work the OLifts twice a week, my personal advice would be to focus completely on full snatches and clean and jerks on those two days. With only two sessions a week, you want to get as much bang for your buck as possible. I would spend both of those sessions doing SN/C&J. If you're a beginning or intermediate lifter, you'll need to spend a lot of time on skill development in the technique of the full lifts. The best way to do this with only two sessions a week is...do the full lifts.
Actually, I've been training twice a week for six or seven years now. I do it because I'm 40, can't handle much more than that, and I work 60+ hours a week. My workouts are:
Tuesday- SN, C&J, Squat (light)
Saturday- SN, C&J, Squat (heavy)
This wouldn't be enough work for a younger lifter, obviously. The point I'm making is that with only two workouts a week, you want to get maximum benefit out of your time. I personally think doing the full competition lifts is the best way to do that.