My advice is only get ONE the first time and try it out. There are so many providers both very expensive and rather cheap. Most tell you what LUMENS they are using but alot of others just say they are bright replacements.. You also need to determine which color of light you prefer. Most folks like the WARM LIGHT which represents the old incandescent bulbs pretty close. Others like the COOL bright type but they give off a BLUISH looking light which I don't care too much about...
Some of the expensive LED replacements have built-in regulator chips that may interfere with your HDTV signals, radio signals, etc.
The best advise is to just get ONE REPLACEMENT first and try it out before spending hundreds of dollars dong them all at one wack just to find out they are not what you expected to get...
Once you get them all replaced they will save around 80% of your lights load to the battery if you are camping off the power grid. That is a HUGH power savings. The LEDs also do not heat up much. When you pull down your current lens etc you will most definitely start seeing all of the yellow plastic around them that is being burned up by the very hot incandescent automotive type bulbs. Be sure to turn them off for a couple of minutes before you reach up in there to twist one out... It will be "MIGHTY HOT" to touch...
Just my thoughts
Roy Ken