A partially facile suggestion, but it sounds like what you want is the Pi 400's board design; unfortunately there's no Pi 500, yet! The current form-factor is

A partially facile suggestion, but it sounds like what you want is the Pi 400's board design; unfortunately there's no Pi 500, yet! The current form-factor is based on the B+ (the B had ports on every single side, if you count the GPIO pins, while the B+ moved the power round to the same side as the HDMI), and I suspect part of the reason for sticking with the form factor is the HAT specification (which specifies physical layout as well as electrical and software requirements), which I think was published at the same time as the B+ was released (my memory's fuzzy on that point, though).