Professional Rider Database
It's unlikely that anyone who has compiled that data would allow you download it.

Cycling News has a really good database at http://www.cyclingnews.com/teams

You can download rankings that include all the riders with name, country and age at http://www.cqranking.com/men/asp/gen/downloads.asp

Other than that I would try the UCI or each country's governing body, but it's unlikely they would have height and weight stats.