Second Jon's Pragmasis or Almax, everything else is history with a normal set of boltcrops/sledgehammer attack/freeze treatment, also minimum Squire S65 padlock.
I speak from experience having had so called good and expensive (£100) lock destroyed very easily before reading alot and finding these two companies.
Pragmasis Ground anchor is very, very good.
If you do a search on the web you will find a man called Zanx destroying all manner of SoldSecure and Thatcham locks ridiculously easy, depressing though that is.
AS a deterrent others may be ok but if they are in there and want it you are going to have to spend some money to slow them down, and preferably fit an alarm too. The XENA alarmed padlocks are good, they also do self contained PIR's for about £30.
Grinders will get through Almax and Pragmasis but they will make a lot of noise and, if you use the 19mm chains, take a good few minutes, and maybe even cause the thieving gits to hurt themselves trying 😀
my loss and insurance claim was eyewatering, I wish I had found this type of advice first….you live and learn.