Since i'm in Houston, I don't need to worry about it being super cold - but it does get chilly, and down into the 40s or 30s if its a cold snap here in the mornings.

What I need is some pants that are good for 40-50 degree with a little breeze. Should I get my first pair of tights? Or are there other options?

I already know I'll be investing in a light/medium weight hi-vis windbreaker for up top, with my regular Asics riding shirts underneath. (though recommendations for jackets are welcome too.