I havent had a c-section, but if I did and I was ready for yoga pants I would wear and buy more of the Green Apple brand. I think they have bamboo or something in them that makes them so soft, yet thin and they dont seem to apply any pressure anywhere when I wear them. Soooo comfy! And since they are yoga pants they have the extra material on top to be able to pull over an incision (I pull them up over my baby bump all the time :)) The nice thing too is that they seem to fit me no matter what. I wore them prepregnancy, during pregnancy, post pregnancy (and now pre and during again). So comfortable! Anyway, Marshall's and TJ Maxx is the only places Ive seen sell them and they are always under $20. Which reminds me, I need to try to find a few more pairs!
As for the top, I love love love bravado nursing tanks. They come in a few nice colors and are so worth the $$. They give great support and easy access for breastfeeding (without a back layer that some have that seem to just get in the way to me!). I think these were all I wore for 6 months after my last baby! They keep the hospital rooms pretty warm for the baby, I think so a tank was all I needed. But being it'll be Feb, I would maybe bring a big comfy (soft) sweater or a big comfy robe for extra warmth when needed.
Good luck!! Wishing you much comfort & joy with your new baby!