Choosing a battery

I've been researching VLRA batteries. This type of lead-acid battery can safely be inverted without damaging the battery by spilling electrolyte. There is also a safety valve that will vent built up hydrogen gas should we overcharge the battery. While our application is weight sensitive, and these batteries are exceptionally heavy (the one I'm contemplating purchasing weighs about 8 pounds), the power to cost ratio is very high. Since we are on a budget, lead-acid is a better solution than, say, Li-Ion or lithium polymer. The battery I selected, which is intended for use in wheelchairs and UPSs, should be able to be discharged(to about 10%) and recharged many many times. The data sheet specifies the dimensions and charging specifications as well.