Absolutely!
My friends were just at the Air Force One exibit last week, it's awesome! You can easily spend all day at that library.
You can stay in Ventura (right on the ocean) for a quite a bit less than Santa Barbara...it's about 30-45 min tops from the Reagan Library. Santa Barbara is about 30 minutes north on Ventura.
Have a great time!
(p.s. I forgot about the "traffic factor" between the library, and Ventura/Santa Barbara route. Miles it's not long, but you can get to SB from the Library in way less than an hour and a half, if you hit it right.)