I was brought to many of our national parks by my parents, as a child. I continued the tradition with our children and my husband, who hadn't seen too many. We are avid road-trippers. If you decide to drive, and you have any questions regarding roadtripping, just ask!
Anaheim to Sea World is definitely 1-1/2 to 2 hours by car, depending on what hour of the day you drive it. Personally, though, I'd go to the San Diego Zoo or the Zoo's Safari Park before I'd go to Sea World. If you are a WDW fan, you will notice a lot of similarities between the Zoo and Safari Park, and WDW's DAK! Yet there is so much more at the Safari Park or the Zoo.
Which one to go to? It all depends on what you want to see. Both of them have their pros and cons, but they really cannot be done on the same day -- they're 35 minutes apart and both are HUGE. The Zoo is located in Balboa Park (filled with many other things to tempt you), parking is free, you can ride the double-decker bus and see the highlights, and do all the walking you could possibly want to do. There are a couple of shows to see. If the pandas are out, those are fun to see. Typical zoo animals to see, but in a non-traditional, more natural environment yet still confined in space. The Safari Park has less ground for PEOPLE to cover, but many of the animals have loads more space. There are many animals that typical zoos don't have, or maybe they only have one or two when the Safari Park has a half dozen or more. Familiar with Kilimanjaro Safari at DAK? There's one of those at the Safari Park, but it is extra $. I'm not sure if the tram ride is extra $ or not. (The last time I was there, I had a free teacher's pass and rode both tram and Safari for no charge.)
Donna