Hi,
I have mac mini as a server (Mid 2010) and its lacks Bluetooth LE support.
I am assuming that anything built with Broadcom BCM20702 would work - but I'm assuming, and that doesn't always work out for me 
Has anyone tested and confirmed working specific Bluetooth dongles on the mac with the Flic Mac client?
just got the GMYLE Bluetooth 4.0 Dual Mode Micro USB Broadcom BCM20702 Adapter Dongle, US $8.98 inc postage from eBay claims to work with :
MacBook Air Late 2010 and later, Mac mini Late 2009 and later, MacBook Late 2008 and Later, MacBook Pro 13" Mid 2009 and later, MacBook Pro 15" Late 2008 and Later, MacBook Pro 17" Early 2009 and later, Retina MacBook Pro Mid 2012 and later, Mac Pro Early 2009 and later, iMac with Broadcom Wi-Fi chip Late 2009 and later)
Works perfectly with no configuration with my Mac mini (Mid 2010) El Capitan, so I'm inclined to believe the above compatibility list.