thanks so much for the interest.
let me see if i can answer all the questions, and sorry for the previous lack of clarity.
a cable COULD be run to the LED module, and the newly created electronics module could be mounted elsewhere, but we would like to put the whole package in the instrument case. this is NOT a limitation, though. the space available is about 1"x1"x3"deep.
as long as it is not extravagant (thousands), money is not a huge issue just yet.
power sources available are +5v, +28v, +/-10v, +/-15v and can be tapped into with little problem.
i'm not aware of noise problems, and have no idea what noise limitations would have to be addressed.
there are no circuit design experts on site, but we are all fairly clever and adept technicians. if it can be designed, we can build it here. thus the need for the help.
if you e-mail me personally, i can send you photos of the instrument we are working on, what we are replacing (and WHY), and the size limitations we are talking about. a picture is worth a 1000 words, eh?
again THANKS for the interest !!!