Looks like you've already had some well rounded input. I have to agree with what others have said. There's not typically a need for most people to go with 6 inches of lift to suit off-road function (which is not to say that NO ONE needs it, but very few anyway).
I'm using Radflo coilovers w/PRG UCA's up front, OME leaf packs, and shocks in back, and I'm very pleased with on and off-road handling(with extra weight when hauling grear on trips).
Something that should be considered when you upgrade is, do you have or will you add a heavy front bull bar type bumper w/ winch, which will add quite a bit of weight to the front, and consequently add dive to it on and off road. This will have you seeking a firmer front suspension to compensate.
Anyway, my 2 cents is this: Coilovers are a performance oriented upgrade to sort out the front, and are great but pricey, but may be an overkill for what some people will really put their vehicles through. If you just want to get a little extra clearance you can pretty much get the same amount of clearance as a full coilover kit, from a lot of the coil spacer kits out there...for a lot less money.