I use a split keyboard with a magic trackpad in the middle between the two halves-- for me, it's so much more comfortable and ergonomic to move my hand toward the middle for mouse stuff, instead of off to the side, and using a split keyboard lets me keep my shoulders in a more natural position with my hands farther apart.
I built my keyboard using this: https://keeb.io/products/quefrency-rev-4-65-split-staggered-... and I've been happy with it for the last few years.