Help with planning a family trip to Costa Rica

I'm thinking of taking the wife and kids (age 8 and 12) to Costa Rica in April. Based on some preliminary research, I was thinking of flying into SJO and renting a car to go to the Cloud Forest and Arenal (sp?) Volcano for a few days, and then driving down to the Pacific Coast (Manuel Antonio NP) for a few days. Then back to SJO to fly home. Is this a doable itinerary for about a week? Anybody have any suggestions on lodging, things to do/see, driving advice, etc. My kids are absolute animal nuts so I thought they would enjoy it there with all the monkeys, lizards, jungle tours, etc. Would be interested in Canopy tours, ziplining, rafting, snorkeling, hiking, etc. Thanks in advance!

Well, wondering if you made that trip. Yes, CR is very doable and fun. Easy to drive there, great infrastructure. Monkey lizards and more for sure. Go to volcan poas if you get a chance. It's in ALAJUELA province, same province you fly into but north another buck and a half ride. Excellent to view. Did you make it?