If you're going to go lead acid I prefer flooded myself. With flooded you can add distilled water while with the other types, they DO vent... once and you can't easily add water. Then they die. That's why UPS batteries only last a few years. Well cared for flooded lead acid cells can last decades. Of course the issue is finding ones that are high enough quality to actually make it that long... all the cheap Crappy Tire ones I've bought usually die with a shorted cell at some point. I have two from 2013 still kicking though, but they also have a fairly easy life just staying on float. Only get cycled when power goes out.
