In the newest releases of JFBConnect, there is a method to let the user go through the standard JomSocial registration flow, with data pre-filled. However, the newest releases of JFBConnect are only compatible with Joomla 2.5 and 3.x. Obviously, if you can upgrade, we'd recommend you do so.
With that said, if your profile types have the same fields to show, you should be able to edit the /plugins/jfbcprofiles/jomsocial/jomsocial.php file. Around line 96, you'll see:
$html .= JHTML::_('select.genericlist', $availableTypes, 'profile_id', ' onchange="' . $profileJs . '"', 'id', 'name', $profileType);
Change that to:
$html .= JHTML::_('select.genericlist', $availableTypes, 'profile_id', null, 'id', 'name', $profileType);
Test that and let me know how it goes. Hopefully that will fix you right up.
Thanks,
Alex