am now contemplating a semi-hollow (or even full hollow) tele type body(please dont hold this against me

e.g. atm i am thinking about routing out a poplar body (around 48mm thick) i have lying around to have a centre block (this will stop around 100 mm from guitar butt; around 90 mm wide) and routing everything else out so that the back is around 7mm thick and the side will also be 7 mm thick
question: do i need to do additional bracing on the poplar back ?
and what if i wish to rout the whole lot out to within 7 mm thick overall? would i need additional bracing?
moreover, for a 7mm thick top (or back) what should the dimensions of the bracing be? thicker than 7 mm? wider than 14 mm?
is there a formula?
presumably quartersawn wood to be used for bracing
also while i am at it...which type of bracing produces the most stiff top (or back) ...i dont want it to vibrate freely at all and it to be as 'solid' as possible
for the top i am contemplating using some 7mm thick cocobolo i have
would the bracing also necessarily need to also be cocobolo?
thanks in anticipation for the words of wisdom to spring forth....