Someone correct me if I'm wrong (it would be a good thing, considering I'm looking at low options myself) but according to the BMW configurator, you cannot have the lowered suspension model without having the ESA option (ie. electronic suspension). If you tick the "Seat height reduction" option (it's name is a bit misleading - it's not the seat itself, it's the lowered suspension) then it will automatically add on the Dynamic ESA option.
edit: I may have misread your post a little, wasn't sure what the implications were, but I'd still like to confirm my options for a low bike... if the standard suspension option gives any options in that regard, I'd be interested too! Short of a 3rd party lowering kit... but for example, if someone said "oh the standard suspension model is already lower than an electronic one" then that would be interested news, for example.