I currently have a Full Face Mask and would like to try the Nasal Mask which are the best ones?

If you would like to try a Nasal Mask to see if they are more comfortable, there are some factors to consider before you decide:

If you have nasal patency issues (difficulty breathing through your nose, deviated septum, enlarged turbinates, etc.) Then transitioning from a Nasal Mask to a Full Face Mask might not be the best solution. A new Full Face Mask like the AirFit F30i is the latest mask released from ResMed and is a hybrid design that is suitable for people who are looking for a more comfortable solution.
If you are a mouth breather, then you might require a nasal mask to be used in conjunction with a chin strap to keep your mouth closed throughout the night. Particularly in deeper stages of sleep when your jaw is more relaxed.

There is several pros and cons to each mask, so it is important to assess your individual requirements.