clearance needed

2"is a fairly standard lift and will do what you want it for, Any higher is usually illegal and gets more expensive. You can also go up a size in tyres.
Cheers Dave

The Isuzu MU-X as is should have no problems with any beach driving ,, just let the tyres down and go for it.

The MU-X is a reasonable height std, depending on the use perhaps an additional set of rims fitted with larger dia tyres will be just as good and other mods.

Since you let the tyres down for a longer footprint when off road and less pressure for sand, the increase in tyre dia will help retain clearance and also add the ability to achieve a longer more supportive footprint to give the traction/grip you may require

Use original wheels for normal traveling.

Because you are going to ADD salt to the menu, long before ever going near sand or salt I would get the internals of each chassis rail internally sprayed with body wax or Lanolin Industrial so at least some protective coating is in there to reduce the risk of Tin Worm infestation. Too much salt isn't good for the vehicles heart either.

Always remember to have the vehicle on a steep slope and hose the island/beach out the chassis rails after swimming in the sea or near it.

If you have seen the TV ads for the MU-X I wonder if some sort of hair product will keep your hair under control while driving.

One mm more than the last bloke who only just made it before you is the magic number ;)
As stated, a little suspension work and a minor lift to keep the body up high enough when loaded with the necessaries is a great start. Going up a size or two in tyres will maintain some load carrying ability with the higher air volume.
A bog standard one will go most places but will bump and grind along the tracks. The above simple mods will see you pretty much unstoppable where others fail on the hot dry days. The beaches are much less of an issue than some of the tracks and their approaches.
Places like cornwells cutting and the mad mile out the back of kingfisher on Fraser will reward you for doing a little prep work.

Bog standard will get u in and out safely....If u drive to the conditions and exercise common sense.

No mods needed. Just drop your tyre pressures and away you go. It helps if you don't overload it or attempt to drag a big trailer through the soft stuff.
Just be careful and stick to the well-used (ie. not overly difficult) tracks to start with until you get familiar with the vehicle and sand driving.

Agree standard setup with correct tyre pressure (18-20) will get you to most places. Having just done 200km on Fraser island some areas are very chopped up and tracks up to central station from eurong will really test your tyres and clearance. There are some rather large drop offs going into lake Mackenzie which will test the rear clearance. I have 2" suspension rise and LT construction all terrains and handled this with ease.
If only intending to go to the beach once, standard will do but as we go to the beach at least 4 times a year I chose to upgrade and also we tow a camper.

I was going to suggest yesterday not to worry about it. But not knowing the car I bided my time.

Looks like my gut feel was correct.

From above comments I wouldn't bother.

We have a 100 series with about a 2" lift which came from winding up the torsion bars, stronger rear springs and putting 285 tyress on it.

Haven't been stopped in any drive from the High Country to the deserts.

Phil

We have the latest model D.Max LS-T and the only complaint I had was the suspension, absolute cr"p. You have coils on the back where we have leaf springs, but the front is the same, we kept banging the bump stops and after replacing the whole suspension and checking the old shocks I could not believe how weak they were.
Bigger coils and shocks, end up with 2 inch rise, you will have a much nicer and safer ride.

Just be careful and stick to the well-used tracks to start with until you get familiar with the vehicle and sand driving.