Here's a Great Battery (420 CCA - 22 Ah) that a lot of Vmax guys use.
http://www.batteryspecialist.ca/12-volts-22ah-terminal-t4-sla-agm-battery-ub12220/
http://www.amazon.ca/UB12220-Wheelchair-Medical-Mobility-Battery/dp/B007L4JXF6
I just bought the APEX battery version of that one (also made by UPG):
http://www.apexbattery.com/apex-battery-apx12220-12-volt-22-ah-battery.html
My last battery was the UB12180 (283 CCA- 18 Ah) and it lasted 9 years.
http://www.apexbattery.com/universal-ub12180-12v-18ah-sealed-lead-acid-ba.html