The following is my opinion
Their reputation is not great which is why they represent good value for money, until they go wrong then consider re-morgaging the house.
So this is what I think
.The 4x4 has problems with a bearing in the transfer boxes.
.Non critial spare parts are difficult to obtain, expensive and often cannot be reconditioned. eg prop shafts.
.I like to do my own car repairs, but with the exception of this forum and one other it is very difficult to obtain technical advise or documentation eg. A haynes manual does not exist. You tube clips are not always available for this car and I think Vauxhall are not particularly forward in issuing guidance to the general public.
. The manual cars typically suffer with vibration at 2000rpm, something that frustrates me.
On the plus side, its comfortable, stable, heavy and with loads of torque so makes an excellent tow car.
Personally I would advise you to avoid the 4x4, unless you plan to tow, my car can tow a caravan, without any difficulty, across a wet field.
The latter Antara cars were 2 wheel drive only and I have been recommended to me as a good car. Obviously this avoids the problematic tansfer box. Given your use the 2 wheel drive derivative would seem quite sensible and your occasional long trip should be sufficient to keep the dpf clean. Richie