The first picture showing is misleading this cradle is part of a fixed car kit install see link
THB Bury UNI CarTalk Base Unit with DSP Larger Image - eXpansys New Zealand then you add the cradle to suit your phone like
THB UNI Take&Talk Cradle - BlackBerry 8100 'Pearl' which charges the phone and makes it hands free with Bluetooth if you look on the back of your pearl you will see 2 brass pins beside the button to take the battery door of this is used by the cradle to charge the 8100 also when its in the cradle it uses the external antenna for coverage though the back of the 8100 were the internal antenna is located, I have the other cradle that you recommended but have found problems with it the speech is not as good as the proper 8100 cradle
THB UNI Take&Talk Cradle - BlackBerry 8100 'Pearl' this is the cradle to get if you respect your pearl (as everyone here does and cant live without it) sure itxxx8217;s a bit expensive but the fixed install will do you for life and all you have to do is replace the cradle when you get a new phone but itxxx8217;s worth every penny, especially since the 1st of march in the UK you get 3 points on your licence and Ł80.00 fine if caught using a phone without a handsfree kit while driving