sean if i were you i would give airtronics a look see.. i have a m-8 and soon a m-11 they are both great radios and the third channel is a reostat type knob so you can use it for your third needle. i have that same setup in most of my boats and it works great just a move of the thumb whild steering and whammo you have just adjusted your needle and now you are ready to fry your glow plug..lol
terminator