I'll post my .02, not an expert here but i'll share what i'm using. I'm currently using the Jabra BT250v. The best part of the design I feel is the earpiece itself. It fits into your ear, channeling the sound into your ear, allowing you to hear better. Other bluetooth models on the market just sit on your ear, letting sound escape around the earpiece. Audio quality is good enough that I can hear a caller in a busy airport or restaurant, and the microphone picks up very well, footsteps can even be heard at times (given right conditions). I've own several other bluetooth earpieces and have fallen back to this one as it's the clearest audio quality, both in the mic and speaker. This one does ring in the ear and vibrate as well, and you can answer your phone with the press of a button. Setup is easy, and pairs with the phone automatically, even if you walked out of range. Not sure if it's loud enough for your purposes, but maybe the earpiece itself would cover that. You can use your finger to hold the earpiece in closer if you're in a really noisy environment and it "seems" to get louder, only that it's just closer to the eardrum. Average going price should be around $50.

Here's a link to the manufacture's website, although I'd suggest looking around as they can be had for cheaper, and may even be found at your local electronics/phone store.

Jabra BT250v, Bluetooth headsets, Mobile, Jabra

Hope that helps!