OP, since we both have 04 Monaco's I'm pretty sure we both have the same fixture. Not trying to be picky but mine take two 18" bulbs which are cool white with a temp of 6-7000... in LEDs that's called bright white.
Here is a
post on how I replaced with LED panels. I like the
warm white (3000 temp) or natural white and I would suggest putting in five panels/fixture ($17.50) plus drilling the holes so you can select how many fixtures you can use without taking the cover off. I do not see that much difference in the amount of light with it on or off.
These new
cree panels look interesting and the cree chips are the future of LEDs, but they need to come down in price a lot before I'll try them ion the MH. I only buy cree LEDs for my home because the older style loose a lot of light output over time. I have 6-7 that I never turn off (cheaper than a divorce) and their output is 60-70% of new after several years of 24/7 use.
