Since you have 3 drives that all are different, why would you want to use them in a RAID configuration? If you add them to a RAID, then you'll lose everything. In addition, important data should always be backed up (a RAID is not a backup solution).
Another question, If I do a raid let say 2 60GB SSD, is that going to be 120GB in total? Sorry for the stupid question.
Only if you setup a RAID 0, but I wouldn't recommend it.