If it was mine . and at £1400 it should be if i was looking for one now ....... I would not worry about the lower ball joints, they are NOT expensive to sort out ( unlike the upper wishbones which you say are ok ) and I would not bother with the cambelt at only sub 100k miles having beeen rerplaced at 63k miles.( albeit some time ago now )
you will probably get many years from the cambelt if truth be known, otherwise it's going to cost you at least £500 to do that alone.
i would be more concerned with the tyres quite honestly ( £100 a corner ) and having a simple oil change, filters and fluid checks service.
If it drives and sounds ok to you, and your happy with the bodywork etc.
At £1400 it sounds a bit of a gift to me.
Malc