Suggestions please for tackle to secure a bike to the ground (ground anchors?) – I realise that nothing is impregnable, but what's the forum's view on the strongest product?

Oxford docking station and zone gold rated chain here.

Oxford ground anchor x 2 and some heafty chains!!

for home use an Almax or Pragmasis chain, and a decent ground anchor like Torc, kryptonite or oxford.

Thanks

The pragmasis or almax will stop anyone without power tools.
the others will stop all but the determined /highly skilled.
Remember though a hacksaw will go through your frame pretty quickly (less than a minute and think how much the components would fetch on EBAY and would be untraceable.

Decent security but good insurance is my preferred route.