I took up westside training 8 months ago, my bench has gone up at least 120 lbs during that time. My squat has gone up about the same, maybe a bit more, and my deadlift has lagged a bit, but still has gone up quite a bit.
For bench assistance, I would recomend changing exercises every two weeks. I like 3 board press, 3 board press with bands, decline benches, overhead pin presses, flat bench dumbells for a rep max, lightened band presses, and rack lockouts. These were listed in no particular order.
For triceps, I like to do a barbell exercise on dynamic day, and a dumbell exercise on max effort day. For example, I will alternate between JM Press, 5 board press, and skullcrushers on dynamic day, and on Max effort day, I will alternate between elbows out tricep extensions, and palms facing triceps extensions.
Hope this helps.