If it is limited to vehicles assembled here and sold new here I'd take a punt on one of the following:

1979-1980 Chevrolet C20 Silverado optioned with TH400 auto, although these don't appear to have been optional with A/C so that may not be all that good in the hotter regions.

HZ Overlander either a van or a wagon, with integrated A/C. Will always be L31 M41, more comfortable with buckets. Option up with power steer too.

Maybe even an optioned up HZ or WB van with a highway diff ratio. A HZ L31 M41 Kingswood van with buckets, column shift, A/C and 3.08 or even 2.60 rear end with LSD would get you most places comfortable with enough storage.

1999 Holden Suburban 2500, although not assembled here. Big diesel. You could vote for a 2006-ish F250 7.3TD auto for similar reasons.

VZ Crewman Cross8 would be OK too with a canopy on the tub for storage.

Depends on the 4x4. My Overlander rode better than a standard HZ cab chassis, it was the lack of legroom and crappy seats that made it a chore. 200 Series ‘cruiser, Ram, Y62 Patrol or Silverado are easy to drive for many kM. Even my Hilux is fine, just not with the standard seats, but with the Recaro Ergomed seat it’s easy. Driving across the Hay Plains unit towing a trailer it would effortlessly cruise at 140km/h if you wanted it to and were prepared to cop speeding fines.

The Overlander were streets ahead of anything else you could buy in Australia in the late 70’s, other than maybe the V8 Jeep Cherokee which actually shared the same basic driveline. In Premier or Statesman form you got luxury too. The problems I found with my Overlander cab chassis were legroom (but any HQ-WB ute or cab-chassis were the same). Plus a 308/5.0L isn’t really the right engine.
With any of he other W size body styles you can fit better seats that slide back further, but the ute and cab-chassis cabin back kills that.
I found with my HZ cab chassis, it was geared OK with the 1:1 TH400, 3.54 gears and 31-32” tyres. The TH400 was superb as they always are. However the 5.0L lacked the torque you need for a big 4x4. It initially had its original red 5.0L and I replaced that with a VP 5.0L. The short stroke V8 needed to be bigger. It needed at least a 304/308 stroked to 350ci. I got a 454 for it (still have it), but ended up selling it and replaced it with a VZ Cross8.

Agree. I’m 6’5” and struggle with legroom in them. The passenger versions I used to get away with by moving the seats back or like my LX hatchback fitted an aftermarket driver’s seat. I fitted a Stratos seat to my 1987 Hilux and a Recaro to the 2011 to give me comfortable leg room. In HQ to WB I did find them far better leg room wise with a bench and column shift as I could stick my left foot up on the tunnel, although those benches were not comfortable to sit in.
Funnily enough I’ve not had leg room or comfort issues in certain other cars. Like my SII RX7, it was awesome. Same with the V2 CV8, VY SS ute and the other really nice one was an FG G6E. This is why I’ve got a pair of black CV8 buckets out of a low kM wreck to put in my HK GTS.

The Overlander was all 1973-4 Blazer underneath including the steering. It steered fine. Got the Blazer front and rear brakes (same as those 60’s Cherokees). The biggest issue was the short front leaf springs which didn’t allow enough differential movement between the front wheels (one up, one down). A bit like the old Hiluxes were. Mine had the standard HZ steering box which I changed to a HZ power steering box, however it ended up with a poorer turning circle. Mine was a good car, but by 2006 a HZ was getting to old and expensive to keep on the road. Doors, guards, grilles, front bar etc we’re getting harder to find. The bonnet inner skin tore under the catch, luckily I had a good WB one in the shed but even then a good one was $400 minimum. Plus being an everyday driver we all know what a HQ-WB can be like cabin rust wise. Finding seals and other consumables like uni joints for the front axle, calipers, wheel cylinders etc was hard. I had to find bits off Cherokees and order other bits from the USA just to keep it running. If I ever busted an axle I’d have to have got one made. Finding parts for the twin stick Dana20 transfer case would have been an issue too. Even the rear springs, although they were GMH, Haywood had added extra leaves. The TH400 column shift setup was all flogged out but it wasn’t standard, it had been altered to clear the front springs, so it either had to be fully rebuilt or changed which I did to a UC Trimatic T-bar to keep it going.