Don't go in their assuming that a) their hand technique is automatically worse than yours because you did boxing b) that none of them know how to box or c) none of their feet are just as fast as your hands. Just go and learn, somethings will carry over very well from Boxing.

I agree with Philosopher stone

just do kick boxing first, and add boxing and tae kwon do to beef up your game

Only way to know is to try it out. I would always err toward trying something out and discovering it wasn't for me rather than not trying it at all and missing something that does work for you.

Tae Kwon -Do is Illicite.

I trained in boxing for about a year and a half, but was lacking the ability to truly dedicate my self due to the cost and the distance. I did have 2 fights, both of which I won and would say that I am a pretty good boxer (natural rythm, speed, etc.). Anyways, a tae kwon-do gym opened up literally a minute away from my house and I was pretty excited to try it out. I've always loved the look of tae kwon-do, though I do understand that it less-effective than muay thai, kickboxing, boxing, etc. I do have a concern though, when I watch the hand striking techniques in tae kwon-do I cringe and worry that I will be unable to flow into them naturally. My boxing is obviously far more effective than any hand striking in tae kwon-do and I think I'll have difficulties adjusting to its 'unqiue' (terrible) style ... Do you think this could be a problem ?