Looking For My First Pair of Full Sized Headphones

Hi guys, I've just joined the forum, but I've been browsing for awhile. I'm new to high end headphones, but I've been a DIY home and car audio enthusiast for awhile. I was hoping for some guidance in choosing a pair of full sized headphones for use at work.

I'm looking for something that allows minimal sound to escape because I'm using these in an office. My budget is $100. I'll be using an iPod Classic for playback and no amplifier. I don't have any plans to add amplification either. I'm looking for something with a fairly natural sound. I'm not much of a bass head and I listen to almost anything. I don't listen to much rap or classical though. When I design a system for a car midbass is always one of my highest priorities (not so easy to do when you're limited to low displacement drivers that fit in a door :P). Overall I would just like the most accurate reproduction of the material being played within my price point.

Looking around I've thought about the Shure 440, AT M50, AT M30, and the AT 700. Based on reviews I think the 700 would be a good choice, but I'm afraid they'd be slightly large and cumbersome to carry in my backpack to work everyday. I'm not looking for an ultraportable, but they seem to be fairly large. I'm also not in love with their aesthetics, stupid reason I know, but I'm just not crazy about the way they look. I'm worried about the external wire on the 440's breaking as well. That leaves the AT M50 and M30. I like what I'm reading about the M30, but some people are saying the M50 is more detailed in the midrange, but the low end can be somewhat bloated. Any advice on what would be a good 'phone for me? I'm very open to any other suggestions, I've even considered the Fostex T50.

Thanks