I would have thought getting LED's listed as dimmable and a switch listed as capable of dimming LED's would have been all I needed to avoid flickering issues; as that is not the case, I'm not really sure what to buy.
LOL there's the root of the problem. Back in the old incandescent days, the three ways to dim were a variac (huge and heavy), rheostat (large and VERY hot), or a cheap new "semiconductor" tech called a triac, which "turns on" electronically, and turns off when the AC current switches polarity. The dimmer adds a timer to delay when it turns on. Easy, but makes a big mess of the AC sine wave.
This works mostly fine on incandescents (it can be buzzy or flickery). However, LEDs are by nature low-voltage DC devices, and use a switching power supply or some cheaper method to convert AC line power to DC to light the actual LED elements inside the "bulb-shaped-thing". Making this work with triac dimming is a big challenge, and that's why LED dimming is such a nightmare of incompatibility.
Even worse, most dimmers power themselves by leaking current through the incandescent bulb and putting themselves in series with it. When in series with an electronic load like an LED, there are lots of ways the two devices can negatively interact. That's why most LED dimmers have a neutral wire, so they can self-power without involving the bulb.
Some dimmer manufacturers publish a curated list of LED bulb models they have tested their dimmer with. You don't see a lot of Utilitech, Feit Electric, Ecosmart, Commercial Electric etc. on there because those tend to be cost-lowballer brands marketed for impulse grabs on the aisle endcap, not reliability after-the-sale. I mean they're reliable as a bargain - you'll have the warm glow of money savings for the rest of your life. So there's that.