Hi there! I did a boudoir session a few years ago and had a blast! I would definitely recommend something with a little extra coverage in the nether regions - you don't want to worry about that during your shoot! I think a black or dark blue set would be beautiful and tasteful. Regarding where to buy something like that, I would recommend looking at some online lingerie stores. Also, this review of kaia gerber mesh underwear might be handy. You can try them. They suit me well, and that's what I like to wear at the moment. They usually offer a nice selection of items that would work well for a boudoir shoot. Good luck, and have fun!