This works for me:
1) 4 sets of 6 reps full range squats
2) 4 sets of 6 reps BARBELL lunges one leg at a time
3) Leg ext for 4 sets of 6-8 reps
4) Stiff Legged Deadlifts 4 sets of 6 (let the knees bend and butt go back as Cutler does in videos)
5) Lying Leg Curl 4 sets of 6-8
Extra...after squats sometimes do 2 more sets of 4 reps with 10%-15% more rep. New gym I moved to has great standing leg curl so hit those if you have energy after lying ones. Also, butt blaster is a great finisher. The key for me is how I feel as to whether I add a few extra goodies.

But 2) will absolutely kill you on the 3rd & 4th set. Worse than squats. Remember, it isn't walking lunges so stand stationary and do one leg then the other. If you get hammies strong in relation to your quad strentgh, the squat movement is very comfortable. When below parellel you'll feel like a spring ready to bounce back up.
Oh, and don't worry about your butt getting too big if you are white...even heavy weight will on make it more shapely.
Finally, no wide ass stances and NO, I repeat NO stopping during squatting at the top. Keep the bar moving or reduce the weight. Don't let the stress come off until your reps are done. You can stop and get extra reps though, once you complete the targetted reps. heh