I'm considering buying a winch, but I'm not sure what to get.
 
I want enough power to pull out a slightly modified LJ that will weigh about 4600 lbs.
 
Will an 8000 lb winch get it done?
 
What is the lightest weight winch available in 8K to 9.5K power rating? I want the lightest weight winch I can get.
 
I think I recall reading the Warn Rockcrawler winch is power rated for 9K, and weighs 52 lbs. Anything lighter than that?
 
What is preferable and why, electric or hydraulic winch?
Price is not a factor, within reason. I can afford whatever I want, if there's a valid reason why it's preferable. The problem is that I don't know what I want.
The rock crawler winch is the lightest, but it has a steep price tag around $1300. Plus it only has 50ft of line.
The easiest way to reduce weight of the winch set-up is to use a synthetic rope and aluminium hawse fairlead rather than the wire rope and roller fairlead. These items alone would take a big chunk off.
 
After that you can go with a 9500 lbs winch. When you are stuck, the suction created by mud or the drag over an obstacle can be much more than what your rig's weight is. So go with the biggest winch you can reasonably carry.
You can get derilyn rollers that really don't weigh all that much (they weigh the same as 2 sodas). Rollers are less abrasive to your winch line under load if getting pulled anything less than a straight shot on to the drum. Synthetics are great, but if you are in an area with lots of sharp rocks, invest in a velcro chafe sleeve to protect the line going over the rocks.
 
Electrics are considered "self recovery" as the have a limited duty cycle, meaning you have to let it cool down durning use or the magic blue smoke will come out and the winch no workie. Can be as cheap or as expensive as you want.
 
Hydraulics are more of a "profesional grade" winch as the have a 100% duty cycle, meaning you can run these things all day long under full load and nothing bad happens to the winch. Some note that the slow line speed is a negative using the stock OEM power steering pump, but others have found that by using an uprated pump (AGR etc.) that the line speed will actually meet or pass a similarly sized electric under load. They tend to cost the same or less than a quality electric winch of a similar rating.
 
Using the search function can help you in your quest to find the right winch for you. Reading peoples experiences will help you to find the winch that fits your needs the "best".