Personally I would be looking for a 4.2 - 4.7 meter tinny (not punt or v nose punt) if you want to head to Moreton or out in the bay. Also wide gunnels. A Yamaha or Honda donk 50hp (40hp at a bare minimum. Don't even contemplate a 30hp).
So this one below would be ticking a lot of boxes. Those 2 banger Yammy's are bulletproof. Looks in good nick.
https://www.gumtree.com.au/s-ad/wynnum/tinnies-dinghies/stessl-truck-4-65-2004-and-trailer-in-excellent-condition/1209080028