Deka has gained quite a reputation for value. They have their own lead refinery meaning they refine virgin lead which is essential for AGM plates. The GC220 is similar in length to a group 24 battery so it would not be wishful thinking to fit (4) of them into a tray. Interstate is a re-brander of batteries. I prefer dealing with whom manufactures a battery. Myself in your position, I would price the Deka and compare. Bottom line is the heaviest battery weights a decision if price is similar. Double check your converter voltage specs against the contenderd.