what gps with apm 2.6

Moving from a CC3d/kk2.1 to something with a little more smarts! I want to hold position at altitude and launch straight up and straight down with no stick but throttle.. the APM boards sound like they can do it all.. but I need a gps and compass.. that's where I get confused.. so many options.. a

quad. -9x controller, 980KV motors. 10" props.. 3s 3000mAh batt. custom wood frame

EBAY options all with different gps and compass options..

Can anyone tell me the difference between the

LEA and NEO ect? will both do what I want the quad to do?

$56.99

APM2.6 ArduPilot Mega Flight Controller Ublox Neo-6M GPS with External Compass F

http://www.ebay.com/itm/APM2-6-ArduPilot-Mega-Flight-Controller-Ublox-Neo-6M-GPS-with-External-Compass-F-/351177765863?pt=Radio_Control_Parts_Accessories&hash=item51c3d373e7

then there is this.. still says NEO-6m but it's much smaller and comes in a case? I don't see the difference..

APM2.6 ArduPilot Mega External Compass APM Flight Controller w/Ublox NEO-6M GPS

there price jumps to $108 with a 6H

Side Pin APM2.6 ArduPilot Mega External Compass Flight Control Ublox NEO-6H GPS

Any advice would be greatly appreciated!