BMW /2 acid glass mat battery suggestions

[Coolbreeze]

I am looking for an acid glass mat battery for my '64 R69S. It should be the same size as the original so that the strap will hold it in place properly.
Does anyone have a suggestion as to what I should get and a good place to buy one?

[48Flatty]

I bought an AGM battery for my R69 at Batteries Plus. It's slightly smaller than stock but with a rubber mat spacer works well and no more acid dripping on the fender from the battery breather.