Every warrior's gonna tell you warrior, every sura is going to tell you sura XD
They both have pros and cons, it all boils down to your own playstyle and how much time you have to invest in this server.
Warrior is good damage, but annoying to tank - you'll have to invest in good eq and alchemy
Sura is super tanky, but lacks damage; most sura farmers i saw 90+ use both dragon and light shamans to buff them and some attack bosses with at least one shaman besides the sura. (you'll also have to invest in good eq and alchemy, but you'll level up an additional shaman instead of just a buffer)