+1 for Mighty Mule openers. Got mine from Tractor Supply on sale, then added electric latch and more openers from Amazon. Used theft deterrent bolts for the latch mechanism, and pocketed the latch itself into the 6x6 square steel post it closes on. 2x2 square tube gate, four rail with stiffeners every three feet, with bearing pivots made from scrap on hand. Probably weighs 100 lbs, but pivots with a finger push. Also use the MM lock on the opener arm, and a deep cycle marine battery. Picked up a plastic battery box at Wally World, sunk a 2'x12" post hole under it, and filled it with concrete. While it was still wet I sunk a length of chain into it, leaving enough to loop over the top of the battery box. Someone determined enough could probably still steal the battery (or defeat the gate), but they'd really have to work at it. Unfortunately it would be easier to pull down the neighbors flimsy chain link gate, then drop back across my property line. I'm working on stacking up enough boulders to make that difficult as well. I was leery of the problems others have reported with the MM stuff, but it's going on three years for mine and I've had zero issues. Oh, the solar panel sits at the top of a 2"x20' pole that is bolted to one of the fence posts, and so far I've had no problems with the buried gate opener sensor, either. That's probably the biggest vulnerability: Someone with one of those magnets farmers use in their cows could probably trip the sensor after climbing the gate. I'll have to give that a try to see if it works!
