I've tried most of the Rickenbacker 12s, they sound nice but the necks are too narrow for me to play. The exception being the 660/12 which is a few mm wider, but used versions are few and far apart in the UK, they also cost somewhere north of £2500. I have a Burns Double Six, which has a wide neck, easy to play, inexpensive and plentiful on eBay; I also have an MIJ Jackson Surfcaster, which I think sounds even better than the Ricks, sadly it also has the narrow neck, so once COVID is over it will have to go. @Jimclarke100 mentioned the Gordon Smith 12 string. There's one on Facebook marketplace at the moment, but at £700 appears to be £250 - £300 overpriced to me. https://www.facebook.com/marketplace/item/447369243239451/ The Italia Rimini at around £650 new gets a lot of love, though I've never seen one myself. Also the Harley Benton from Thomann is a very cheap option at £169 plus taxes and shipping from Germany.