Yes, there is the standard 121 "Commuter policy", with a few catches to make it toughter on you. You have to give youreself 2 CAL or Express Jet flights that will get you to your domicile at least 30 minutes prior to your show. However, 24 hours prior to the first flight leaving, you have to have checked the loads, and both flights have to have at least one seat open. So you can't use two flights 12 hours from now that are both oversold, it won't count in the eyes of the policy.
No, you cant reserve the jumpseat. I dont know any passenger 121 airline that will let one pilot "lock" the jumpseat for himself. More than one hour prior to depature, the jumpseat will be awarded to the most senior CAL pilot who has requested it. If no one has requested it more than 1 hour out, from 59 minutes and counting, the jumpseat is given out on a first come first serve basis.