Hi JiaXian,
Ref 96 is really appealing, specially when you see CL's post upper the forum!
Ref 3796 is interesting too but if it has to be around 30mm I'd prefer a 96's 12-120.
Ref 5096 would not be bad but probably so rare.
Ref 5026 would be the perfect deal but perhaps not easy to find, or more expensive, I don't know!
Ref 5196 is quite nice indeed, modern, beautiful, readily available, all the advantages of a current PP.
Ref 5396 is amazing but not the same league anymore!
In fact I'm quite open, and once I have a budget allocated I could even choose one without a "6"!
Oh 5016 has a "6". 
Cheers and thank you for your help.
Dje