Best way to drive from Montezuma to Arenal Observatory Lodge in Costa Rica?

Hello, i am looking for some advice on Costa Rica driving. I will be driving from Montezuma in the southern tip of the Nicoya Peninsula to the Arenal Observatory Lodge and am wondering what the best route will be. I have looked at a map and it looks like I have two options. Option #1 - Montezuma to Paquera and then catch the ferry and then head to San Ramon and then go North on 141. Option #2 - Montezuma to Paquera and drive around the Gulf of Nicoya by taking Highway 21 to Highway 18 to Highway 1 to Highway 142? Also, if there is another route that may work I would appreciate the advice. I will be driving a small 4x4.