First off, none of my banks have a fence, and second the White House fence covers one city block. Fences have their applications, but imho the entire southern border of the US is not one of them. I maintain an Isreali manufactured Yael 15 fence for my employer. The cost of replacing one sensor and PCB is almost $7000. Our fence is only 2.2 miles long, and you want to build one 1200 miles long. Trust me, if you don't monitor the fence with troops anyway, it will be defeated in short order.
Old-fashion fence with patrols (just like now) is the solution that works. Let’s start with 200 miles first year (in most approriate locations) and see how it goes.
Besides, that means shovel-ready jobs.
Fence, e-verify and state initiates would largely solve the problem. That’s why amnesty hacks are in panic mode trying to prevent them.