welcome to the forums
And as for what job you should choose ... it really is up to your playing style preference. If you like partying or want to save on mesos, go with a cleric. If you like mobbing and freezing monsters so they cant hut you, go with Ice/lit. But if you like raw power, go with f/p. My personal preference is ice/lit. They are fairly common, if you total up the populations of the 3 mages, it would probably look like: Cleric>Ice/lit>Fire/poision
but thats just my observation