As to going beyond the typical drill press throat depth, think outside the box ( and upside down ).
I want to do large live edge panels that are way beyond the throat depth of my current drill press ( 7 1/2" ). I have a dremel plung router ( too much slop ) and the reviews on the drill guides are iffy at best.
So I thought that I could beef up the rafts and mount a drill press upside down above a workbench, remove the head from the column and reinstall the head, what would now be right side down. But most drill presses will not allow this, but there are some. Here is one example:
https://www.grooves.land/bosch-tischbohrmaschine-pbd-bosch-hardware-electronic-pZZa1-2097583520.html?language=en¤cy=USD&_z=us&srsltid=AYJSbAd-dcHA4dK5-N-c6ABb6X-Jvf0254o1vej3oStdj7F6thsvPn61w14.
I have not done this myself, yet. Just thinking outside the box.