I would check out Amazon. I've bought several different LED lights from them, and the prices are very reasonable.
Regarding size, there are a lot of options. The one I show here, is actually a flat type of panel, that just sticks up in the RV light assembly, and uses a sort of multiple connector kit to let you hook up to different types of sockets - of course, most RV use the T10 wedge base. What I like about these, are all the light shines downward from the fixture, so the light isn't 'lost'. They have several sizes, like a 20 SMD, 36 SMD or 48 SMD, where SMD refers to Surface Mount Device meaning LED. This is one of the 48SMD little panel. http://www.amazon.com/Cutequeen-Trading-48-SMD-Festoon-Adapter/dp/B00FKPJJNY/ref=pd_sim_auto_2?ie=UTF8&refRID=0H0C42APNB3HZ49TDE7P
I like this, because it is real bright, and you don't have to worry about the heat like the incandescent bulbs. If it's too bright, look for one of the smaller panels, or because their is no heat, you can put a piece of black electrical tape over some of the LEDs without a problem.
This may not fit in your fixture, so don't order enough for all your lights at first. The LED bases are polarized, so you might need to flip the base 180 degrees to make it work. Also, I've found for all types of LED wedge bulbs, the fit in the socket is very sensitive, but once I got them seated in, they worked without a problem.
Ed & Mary
