Joint degrees have pluses and minuses.
Plus - you get to study two subjects and to see the cross-overs between the two. It can increase your employability - more versatile, greater breadth of study etc.
Minus - your timetable is split between two subjects therefore you cannot do the same number of course units as someone doing a single subject degree in either subject. There will be timetable limitations on which units within each subject you can do. That can sometime be frustrating.
For PGCE - you need to look at PGCE course pages and if the info isnt there, email relevant Unis and ask.