Hi guys! I am trying to build a low-cost UAV for mapping, initially I intend to use a flying wing of 1.5m wingspan with  ardupilot APM 2.5, GPS uBlox LEA-6,  2200KV Brushless Motor (2200KV Turnigy 6 D 2826) and Camera Go Pro Hero II, I wonder what the most viable way for me to get a longer flight around 30min, using batteries in parallel? Also I plan to use a long-range radio (Dragon Link) with an antenna tracker (helical or yagi) someone could tell which antenna tracker has the best cost benefit? Thanks for  the fundamental support of you.