Europa-List: Tacho Advice

[Peter Rees <peter.rees05@ntlworld.com>]

Hi Guys - new here so, hope this works.

I'm after a tacho that includes an 'hours run' indicator that incriments at a 
rate
proportional to the engine speed (as opposed to time) so that we can charge
for use of the aircraft based on how hard rather than just how long the engine
has run.

Does anyone have any suggestions of a suitable instrument and if so, were I can
get one?

Thanks in anticipation

Peter (G-MFHI)