I've always stuck with either NRMA or AAMI for all of our insurance policies. I've found most others have too many exclusions, or have a reputation of being difficult to deal with when a claim is made. I know a lot of insurance only covers policy holders if they are on a gazetted road, so technically if you park your car/caravan a few metres away from the edge of a road you may not be covered. It also means I wouldn't be covered driving on our rural property.

If you have a look at an independent customer review site (I would ignore Google reviews or AI responses) you can find some interesting comments about some insurance companies. It's worth actually reading some reviews to see how they treat their customers in the event of a claim. A percentage of the reviews are from people who are happy with the cost/experience in getting insurance, whereas I think it's more important to read about how the provider peforms when there is an actual claim on insurance.

I usually start with www.productreview.com.au/

There are a couple of specialist van insurers who seem well regarded - CIL and KT. KT has a tie-in with the CMCA. CIL got a bit pricey for me, so I switched to KT. I do not have any claims experience.