Champion as in Champion Systems clothing? If that's what you mean, my team uses them for our uniforms. I'm not particularly fond of their stuff, but that's just my own opinion.

In terms of size.... I'm 5'5.5" and 124 lbs; 32C or 34B; size S shirts; size 4 pants. We have the race cut jersey and I wear a size S and for the women's bib shorts I wear a size M. That combo fits me perfectly.

If you have the option, choose the jersey without elastic on the bottom or sleeve hems. Their jersey cut is a little too short (IMO) in the torso length so if you're wearing it the damn thing will slide up to your elbows in about .2 seconds. ...they're okay as long as you don't move at all. Their bib shorts are okay...the chamois is somewhat thin, leg length goes about 2/3 of the way to your knee, elastic keeps them in place nicely, the material however is relatively thin on the shorts and shows wear/fading after a year. Whatever you do make sure it doesn't have white as a background color! (we had those last year and absolutely regretted it...98% see through )

That's my evaluation of Champion Systems clothing. Our team used them for last year's and this year's clothing company. They did have big improvements in their products since last year but I still don't love them (yet?).