For cases around $100, I'm guessing the Antec P180 is the way to go? Looking for something visually simple and elegant..just an option. Lian-li case might be an option, but the Antec P180 seems visually nicer.
If you want visually simple, elegant AND has silent deadening qualities then look at the Antec Solo. The case is made with sound panels for reduced noise and has an excellent cable management system. I think the people you are buying for sound like they would like the small/medium footprint. It has plenty of room to work with though trust me. I have this case and I have tons of stuff in there but I can keep everything neat and tidy. It is also built very well and isn't made of a bunch of cheap plastic. The piano black glossy finish really looks nice as well and definitely fits the simple, professional profile your friends are looking for. With the style your friends are looking for and the sound deadening panels this case is an excellent choice. BTW it has great cooling as well. I have processor, vid card, ram all OC'd no problem.

I think you would be fine with your PSU but the FSP would be a good choice as well. Can't really go wrong with either.