Arials dodge pretty well (with 25 dex and all), which would make you assassin a good tank.

Bird RP is fun.

Assassin I recommend due to the good survivability, and the class is definitely interesting, even if you would choose to PK at some stage (as there are many tactics you could employ as an assassin), though you could rank to Hero first and PK then (or try some assassinations around rank 36 or so, if you choose to do so), that way you would get your first Hero, and people don't die so easily at Hero ranks.

You could read my little assassin survival guide previously posted on this forum as a reply to similar question. Assassin gear would be a balanced set consisting of hp, hitroll and damroll. Fungors (my Herald arial assassin) hero set gave something like (150 hp, +20 hit +30 dam).

If you like writing and artistic stuff, going Herald could be fun for you. Having friendly cabalmates and being a part of some cabal is a fun experience which will increase your deleting treshold (also, Heralds are pretty helpful, and being one could earn you a nice set (even though you don't have cabal pit to gear yourself from as a Herald), though it is not the reason you join the cabal).