A properly maintained low antimony starting battery will outlive a properly maintained "Deep Cycle" car jar battery, when used as a UPS standby. I love the ability of low antimony to shrug off higher voltages of converters. But really the decision is best made by the OP. He may have an inkling that he may someday boondock for a night or two. This isn't a big rip-roaring damned-if-you-do-damned-if-you-don't decision. The newer breed of Johnson Controls batteries contain less antimony than their predecessors. A definitely wrong choice in this instance would be the 5% antimony 6V golf car batteries. All positive attributes of this battery would be unused, and all the negative attributes would stand out like a sore thumb.