Lemforder is oem manufacturer and are roughly $180 each, if you can get it cheaper than that from the dealership go for it. Just for the pure fact that it's lifetime warranty, I'd do it in a heart beat.I checked the oil level this morning after letting it sit a bit longer than 10 minutes and it measured 1/2 qt low.
Doing the control arms myself would save money, that is a great idea. I'd still need to have it aligned but at least the clunk would go away. Are parts from FCPeuro different than the dealer parts? The local Land Rover parts guy gives me discounts so I won't need to pay full price.
If you have Firestone Complete Auto Care around you, I'd highly recommend getting lifetime alignment from them. They're decent enough to get it aligned "straight" if you have the Gap tool and put it into tight tolerance mode. I have them and they're "nationwide".