Hi Ted, I changed my clock bulbs to LED's a few months ago, marvellous! I used a British company, Classic Car LED's. Very useful website and good quality bulbs. I installed green LED's, type 233. I would not use white ones as they distort the colour of your clock faces, the light content id totally different to filament bulbs. That's why they tell you that if you use a LED in your rear light you must buy a RED bulb, if you use a white one the resulting light output is a pale pink, as seen on some boy racers hot hatches! There is no heat problem with them, they run cold, and draw a miniscule amount of current. Re. the idiot lights, I just replaced mine with standard filament bulbs, LED's in the indicator repeaters could upset the flash rate, the neutral light is on rarely, a bright blue LED main beam warning is the last thing you want shining at you on an unlit road, and if the red oil light suddenly illuminates I doubt if you will be worrying about whether you like the type of bulb!!!
PS. If the attached pic works, the idiot lights are standard bulbs.