For ab wheel I like trying to hit 50 reps in as few sets as possible. Not sure what your ab strength is like, but you could start with 10 sets of 5 and then aim for 5 sets of 10+. Keep the rest 1-1.5 minutes
Bi/Tri Superset Ideas
Cable curl and rope pushdown (not sure if you have access to a nautilus machine)
DB Curls and DB Skullcrushers
1 minute hammer curls and ???