Hi @bookloverblue! I had trouble with this one. Sorry.
Decayclownsims has some great platform shoes but, you would need to go into Sims 4 Studio and change the permissions for men to use them. That is simple enough. Just download
Sims 4 Studio (it's free to join their site to access the program). Open the program, press "My CC"; from the list on the left choose the Decayclownsimsfile; on the right tick the box next to male then apply to all swatches, yes, okay, and do the same for masculine; choose "Okay" at the bottom and voila!
http://decayclownsims.tumblr.com/post/106003598219/g-o-t-h-p-l-a-t-f-o-r-m-s-h-o-e-s-female
http://decayclownsims.tumblr.com/post/105726132714/cybergothplatformboots-standalone-non-default
These are some platform converse sneakers that are already unisex:
http://www.lumy-sims.com/2017/04/pixicat-converse-platform.html *music on site
I didn't find any bell-bottoms for men and no disco style bell bottoms for either sex. If you have Movie Hangout, maybe the pants from that would work? You could also try the permissions thing with these flares:
https://www.thesimsresource.com/downloads/details/category/sims4-clothing-female-teenadultelder-everyday/title/flared-hippie-jeans/id/1373149/
http://modthesims.info/d/561810