Hi. Thanks for your post.
Please consider the Garmin Mobile for BlackBerry with GPS 10x below
It comes with a GPS receiver, maps (you actually download the maps as you drive via the data plan/Internet connection on your phone), and 1-yr subscription.
Alternatively, you may consider the Globalsat BT-359c below with Garmin Mobile Maps (free, to install just point your phone's browser to www.google.com/GMM).
NOTE 1: GMM only provides turn-by-turn visual instruction and it does not provide voice prompts, auto reroute if you missed a turn, and many other features that are available in the Garmin software.
NOTE 2: Garmin Mobile software for Blackberry will only work with their own Garmin receiver and does not work with all other 3-rd pary Bluetooth GPS receivers.
NOTE 3: Globaltop G66 uses a baud rate of 5hz (5 updates per seconds) and it may not work well with GMM on a BlackBerry. Pls avoid it and consider the Globalsat BT-359c instead because it has been tested and confirmed to work well on BlackBerry phones.