Only you can decide what's more important to you. Looking the way you want to look, or earning the money to do the things you want to do. Nobody else can decide those priorities for you.
Well, since it can take a long time for hair to grow, those around you will have time enough to get used to it....if they do make accusatory comments when your hair get's to a length they find offensive then re-access the idea at that time. If you don't give a shit, think they can live with it and don't expect to lose your job, then fine, continue. If not, make a decision to do something about it.
My opinion is that if it wont get you fired then why not As Dibbly said there, they'll see it slowly grow - see how that goes down. You might be suprised, they might not mind as much as you think. You might even change their minds about that sorta thing, if they know you're a good guy and that then it seems unlikely you'd be shunned all of a sudden.
you should never compromise your values if they really mean that much to you. if you don't mind compromising then thats great, but will you trully be happy in your job if you don't go with how you feel? as the dok said only you can know whats right for you to do! namaste x x x