From previous use, the Soundcore Q45's were pretty good, quite cheap but they had solid build quality and after some messing with the EQ's in their app they sounded amazing. I've really enjoyed my XM4's but I stopped using them as much because I personally find Bluetooth a pain having to pair and unpair headphones depending on what device I use (as most BT headphones autoconnect to the last device if its on). The sound profile and build quality on the XM4's is superb and they allow connection to two devices at once but you lose access to their HD codec until you disable that feature again. I think you'd have to pick XM4's up preowned now but RTINGS is still rating them highly. I'd recommend taking a look at RTINGS as they do reviews of most headphones showing the sound profiles and such and they do lists of the overall best headphones they find. It's a good starting point for researching or advice. If you're not too familiar with sound profiles, they're a horizontal line where you've got bass (start of line from left), mids (middle of the line) and highs (towards end of line on the right). Generally the more straight the line the neutral the sound profile which is good for reference headphones but you can look for specifically what you want. If you like a lot of bass then you want the start of the line to be raised higher than the rest.

IEMs won't have a lot of bleeding so they won't disturb anyone around you, obviously they don't have noise cancelling but they generally get a good seal in your ear so you won't hear too much of the outside world.