If the ring lug size is not to your liking, you can get these bus-bar options - then you would need to make two pigtails with ring lugs to supply each of them
These allow you to mount them wherever you choose of course
I just ordered M6 washers with 18mm OD from Grainger. 50 in a pack -- probably 46 more than I'll ever need - if anyone would like me to mail a couple, could be arranged.
Maybe even 48
I would think 'under' would be served by the OEM cable lug - the bottom one won't hurt of course, just more of a 'faff' if you have to remove them - in which case that's where the extra 46 comes in, when it drops into a black hole when you unbolt it
Incidentally another 'extra' set of battery terminals (for those with two post vs four post batteries) are the other ends of the battery cables i.e. the engine ground and the starter terminal - of course those aren't so readily accessible if you do need to remove the individual accessory, however most of the time the main thing that is being disconnected is the battery and not so often that you just want one accessory disconnected.
I just ordered M6 washers with 18mm OD from Grainger. 50 in a pack -- probably 46 more than I'll ever need - if anyone would like me to mail a couple, could be arranged.