So I would get a ground anchor like the GRANIT™ WBA 75 from ABUS and then use the GRANIT™ CITY CHAIN XPLUS and that will be a good solid lock solution if you want to avoid U-locks. I don't bother with other brands or companies claiming this or that. I want a company I know I can trust and ABUS is that company. They are not in the business to just get a sticker on the lock so people think it is secure they are in the business of making the lock exceed the basic tests to get that sticker and making sure they are putting out a high quality product in their own factories and making sure it works.

Don't use home despot chain and a cheap (or expensive) master padlock or anything like that. Most of those chains are not designed for locking and security and can be easily defeated and master locks are just easy to get into and generally poor security. Don't trust a large chain store that doesn't specialize in bicycles or motorcycles to get security for those products. Thickness does not always equal security it just equals thickness. I trust the 8 of 15 chain from ABUS more then I would the thickest home despot chain that came from China. Having tested that chain vs. the highest security Schlage/Kryptonite chain it lasted a lot longer. The Schlage chain was busted by a sledgehammer in two blows, the lower security ABUS chain didn't brake after 10 minutes and different people hitting it over and over and people eventually got bored and tired. Sure that is anecdotal but was a fun experiment.