I really like the Hincapie bibs I got from TE, and they have a clasp in the back for easy pee breaks. It's actually quite well designed. I do think they run a bit large, so that's something to consider. I'm a fan of bibs for long rides for sure, and alternate between these and my Louis Garneau bibs.

I also like my Louis Garneau Corsa shorts if I'm not going to wear bibs.