Yuasa, yep good batteries used as standard equipment, especially on Jap cars. The Mrs had one for years on her old Honda civic with no probs, and the newer civic has got one too.
I replaced the two batteries on my 120 which were knackered, with the bigger, slightly uprated Varta, IIRC 950amps, as recommended by Trevor on here. They fit nicely, taking up all the room without touching anything else, also from Tayna.
I like the twin battery set up as Juddian, having that as standard on my 78.
There are lots of guys though, that have opted for 1 normal starter and 1 leisure, for camping etc.
Horses for courses.