Oh dear..so many different options!!
I can only suggest a blue tongue from personal experience...but I personally think dragons are much more interesting to look at.
They are active, interesting little criters just like vitticeps but are heaps smaller so they dont eat you out of house and home. That also means they poo less which is great if you're the one cleaning the cage. They dont require that big an enclosure, a 3ft aquarium is big enough for a pair. They mature fast (one year if fed well) so you can start breeding in a short time. Also because of their size they are also great with small kids and wont hurt your kids if they happen to get bitten.
Central Bearded Dragons win in my opinion, They are awesome lizards with such personality.
Shinglebacks would have to be one of least favorite lizards, i have one and it's a poop machine.
is this your first lizard, but you own snakes?is that right?:?
i would say just a blue toungue or a beardy would be an ideal pet and beardies can also be great colours so you can have him for show when visitors come. shingies (shingle backs) are also great and usually tame.
if you want action get a small monitor or a dragon for eg. a beardie or a pygmy mulga monitor.
But blueys and stumpy's are very tame.
Maybe try a cunningham's skink, they are very fiesty but are lovable when tame