Alternately, you could go for a dual momentary switch as a simpler alternative. Normally-open doesn't seen particularly useful for the ES5, so you'd be fine if you skipped out on the toggle switches. Plus you could always add them later if you decided that you needed them.
Here's the switch, https://www.mammothelectronics.com/products/4sfsspst-m
Just wire one lug to tip the other to sleeve/ground (mono 1/4 jack). For a TRS 1/4 jack for two switches, solder one lug of each switch to the ground lug of the jack. It doesn't matter what side of the switch is ground. I use two switches and it works great!