I have to admit that I don't have a Brooks saddle, but I did spend some time this summer trying out new shorts. The Shebeest Ultra D had a substantial amount of padding--too much for my taste--in the sit bone area. I ultimately settled on the Sugoi FS short, which also offers good padding in that area, but it's a little more "concentrated."
I can't help you with your original question b/c none of my tights are padded, but I did see on TE that PI sells an Ultrasensor tight with the same chamois as the short. Sounds like they might work for you.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher