Both of those siggys are the perfect size to go with your Pitapata - just make sure they are one on top of the other.
The siggy is 500 wide x 220 high
Pitapata is 200 wide x 80 high.
So the widest part of your siggy and pitapata will be 500 (because your pitapata is narrower than the siggy)
The height is 220 and 80 so that reaches the 300 high total allowed.
To illustrate how it looks - look at Jan's siggy that is exactly 600 x 300 - i.e the total size of the box allowed for siggys.
Your Pitapata will fit under the birds feet to just under the dragon's feet and then you siggy will fit over the branch and across - does that make sense - lol!!
Beautiful siggys as usual Jan - well done