OP, it's all about priorities.
You must perform a personal cost/benefit analysis regarding your running and your appearance.
Anyone over 6ft needs to be VERY thin in order to run to their potential, especially as the race distance goes up. There is no getting around this fact.
So you must decide if running to your potential matters to you, or if you would accept reduced running performance in exchange for "improved" appearance.
My personal experience: I ran 14:15 5k when at my racing weight of 159lbs at 6-2. Achieving this weight was not "natural" for me; my body, if left to its own devices, stabilizes at about 185lbs. I had to consciously act in order to achieve 159.
After it became apparent low 14s was about my limit, and I would not be a 13:15 man, I decided to de-emphasize running performance. I began to weight train for the first time ever (while still running at a reduced level). As I said above, I was "artificially" low at 159, so I very easily packed on lean muscle by lifting and eating cleanly.
It is especially easy to look great in this situation because you have very low body fat to begin with, and then start packing on muscle. I admit that I very noticeably became more successful with the ladies, which pains me to say because i'm a runner to the core.
I agree with the poster above who said it sucks that the joy of racing fast can not be combined with getting larger.
My times got much slower, but I was also running much less. It would be very interesting to compare If I was 25lbs heavier but still running the same amount--but this may be impossible (gaining significant muscle while still running seriously). I think the two are mutually exclusive.
The only recent "serious" runner I can recall who seemed to lift a lot and still run well was James Neilsen?