Buying a caravan

I already have a Camping Trailer I'm happy with, but it won't be as useful, comfortable, quick to set up or as versatile as a caravan for most of the trips we're likely to do. We'll either use the C/T for some of our strictly camping trips or sell it. Eiher way, we're considering what we could get for between $40k to $45k that'll be suitable for a family of 4 (kids 9 and 7) with a double bed to fit my 6' 2" frame and possibly a shower/toilet. Our tow vehicle is a 2003 Prado GX 3lt Turbo Diesel. We live on the Central Coast of NSW and have only glimpsed at our local dealer, Coromal so far. I may be naive in what I can do with the caravan, but I like the idea of say, stopping for a powernap and being able to enter the van for a proper lay-down in a queen bed instead of winding the drivers seat down. Stopping at a rest area beside the road for the night to save on costs, etc. Not setting up/packing up in the rain and having to set it all up again to dry it out at home. Stopping beside the road for a quick cuppa and be out of the flies/wind/rain. Visiting friends towing our own accommodation when they haven't the room for an overnight stay. The list goes on! Having it so the kids have a bed each. Bunks or something that folds up after use? I'm 47 and want to keep the van into our eventual retirement to use accordingly.