I've tried numerous setups on both my 90's and my 110 (my main overland truck), and I'm happy with the following:

Bearmach HD springs front and rear
LR OE helper springs for rear
Matt Lee dual shock mounts front and rear - replace standard nuts with nylocks
Monroe Adventure (Gas Magnum) 4x4 dampers, dual, front and rear
Polybush orange (mid-stiffness) replacement bushes
Scorpion Racing heavy-duty anti-roll bar (rear)
Scorpion Racing heavy duty track rod
OME Steering Damper

I like the dual-shock setup, not just for the "two work less hard than one" reason, but also because they're cheaper and you don't really have to carry spares (just remove the broken one and it's counterpart on the other side).

I'm really happy with it, but as Darrin said, there's a lot of personal preference in it.

HTH.
Nick.

Why the 2" lift? A lift offers few benefits for an expedition vehicle, and raises the vehicle's CoG, and makes handling trickier, especially with a heavy load. If you want to accommodate taller tyres, (or -bleah! - wider tyres), then a lift may be a necessary evil.

I'd keep it simple - HD OEM springs, with good gas-shocks (I'd probably choose Bilsteins).

I'd also remove the anti-roll bar if there is one, and put airbags in the rear springs - I bought mine from Dingocroft in the UK. The airbags help reduce body roll and generally assist the rear springs, but can be deflated when you want full axle articulation.

Michael...
Sadly, sold the 6x6 recently :(