MBTX12U fits, just search on that auction site for a Motobatt Falco battery, they are a universal fitment, you can mount the terminals on the front or back of the battery, all four corners are threaded for terminals,comes with a spacer plate to fit underneath the unit to make it the right height .
Yes, you may find others with a bit more CCA but I can testify you will get a good few years from one of these,they work, simples
![:smt002](./images/smilies/002.gif)