For prebuilt, definitely an Iris keyboard without including switches and omitting the middle plate. If you're fine going smaller then I recommend a prebuilt piantor which is similar to a corne but has a more aggressive pinky stagger. I very much recommend the Iris however since it's the sleekest and well designed for its price with integrated rp2040 MCU making it feel "premium" compared to others in its pricerange with the pcb and mcu exposed in some manner.