I would suggest trying to hire one of each for a day on the water.
Everyone has his preferences, I like my 11 foot tinny, it's an older
savage and does me quite well but there are several things to consider.

Motor size. I use a 7.5 most of the time and find it ideal for use with
a car topper. The small motor is easy to carry as I used it with my
hilux with the boat on top. I find that I can use anything between 3
and 30 depending on what is available. The punt will take less power to
do the same speed will plane at a lower speed and usually chew less
juice. You could consider an electric for use on impoundments and with
small modifications have a dual battery system in your car. The
electrics are light, small and can make an excellent backup.
You have stated quite a few places down south that I am not familiar
with that you wish to fish but if you are doing an all over tour of Oz
consider some of the other places. I fished the Rockhampton area and
the Barra are usually the go. Either boat is great for a Barra or jack
in the river or the creeks but mid winter they usually go a bit quiet.
Mackerel are there to take up the slack and a short trip off the shore
can be rewarding most mornings, even in a tiny chop the punt can be
unpleasant but if you pick your morning and your conditions anything is
good. I have even rowed out and caught a few out from the singing ship
in Emu Park. Having a 15 or larger motor opens up a whole new horizon.
Most places you go the fish will be not right at the boat ramp (in
Rocky you have to go at least 100m for Barra) and as I have seen the
river with the tide against the wind produce 1m+ waves consider that in
some places it gets worse than that.
I have fly fished by sitting on top of the 25hp and found that
comfortable but for standing nothing can beat the punt.
Both are great, if you want a fishing holiday where you want to catch a
feed almost every day and try every hot spot get a dingy, 1 petrol and
an electric motor. For a holiday where you might want to do some lake
or creek fishing and want a stable and trouble free fishing platform or
if you are unexperienced with small boats the V-nose will serve you
well.
The V-Nose looks better on the car and seems to be trendy.

Now you need someone to rip holes in that reasoning to have a good
understanding of both.
I'm now stuck up here in Lae where there are too few tinnys and the
small boat is a 22 foot banana boat. The Black bass yellow fin and the
bill fish make up for it, now where did I put that 50W.