Hi and thanks for your compliments.
Most important features for Bluetooth GPS receiver is accuracy and cold-start time / time-to-first-fix (TTFF). Any of our top 5 Bluetooth GPS receivers (click here) will work for you without any problem. If you need data logging funtionality, QStarz Q1000 or Wintec WBT-201 are two of our best sellers. or the latest Q1200 is also very good and has the longest battery life of 49 hours.
Fugawi has a 10-day free trial software and you are welcome to try it here: http://www.fugawi.com/web/demo/version4.htm
For Geocaching, please also check out BeeLineGPS (click here for free trial) or Vito Navigator.
Hope this helps.