Yet another vote for those Bravado ones! yeah, they're not super supportive, but you won't be on your feet & super active the first few weeks PP anyway. So they do the job.
Mine also had space for the Medela 'soft shells' I wore to protect my cracked nipples (hard plastic semi-spheres that stopped anything from touching my nipples. Awesome!)
I also read that underwire could cause plugged ducts, but I LOVE underwire. I did buy an underwire bra at maybe 3 weeks PP & never had a problem. & I'm glad because I wouldn't want to have gone without it for the 23 mos I BFed DS until he self-weaned!
Getting fitted is a great idea in theory but may not work out so well in reality. Unfortunately the selection in my area is pretty bad & the clerks in retail stores didn't really inspire any confidence that they had a clue what they're doing. (Had the same issue with regular bras.)
www.birthandbaby.com has tons of great tips, a massive selection, and an easy return policy. I highly recommend!