Backlight Modding Questions

So I'm working on my very first backlight Tamagotchi project. It's slow going as I've only recently learned soldering and circuitry but I understand all of the components and what I need to do, I'm just struggling with the light diffusion.

I don't want to use a Gameboy mod kit. I'd really rather rig up some LEDs and diffusion film myself. I initially bought some 0402 LED lights but I don't think they have enough power. They also don't have a bead or lens of any kind. My next step is to try a larger LED (maybe 1206?). I'm mounting them on the edge of some frosted acrylic type material at the top.

My question is what LEDs you've used in the past if you've done this project. How did you mount them and get a good diffusion across the screen?