custom instrument panel

[crackajacka]

i want to get rid of my instrument panel eventually and install all new gauges, everything on it is electrical. could i get away with installing gauges in the bezel and running all electrical gauges except the speedometer unless theres a mechanical 2 electrical convertion box like there is for electrical to mechanical. but has anyone done this? what size gauge would fit in the holes for the speedometer and fuel gauge?....... or should i just cut out a completly new bezel and cut out for custom gauges? could anyone give me advice, as i could do this pretty cheap.