You can have..However it is mandatory to have Informatica server and DAC server on the same machine.
Having client in the same machine along with the server is not a bad idea but it is advised to have all the clients installed in another machine.
One more in architecture. How can we have dev , stage and prod instance with optimum utilization of resource..
Can we have dev, uat in single instance and Prod seperately..
If yes how the ETL tier be?
I wil say you have only two instances one is UAT and another is PROD.
Another option would be first pointing your DEV instance do a data load and then point to UAT and then do data load.
In that way you can reduce one set up hardware's.
But its entirely depends on how much hardware your comp/client procure and also on your decision on having 2 or 3 sets of environment.
Mark correct or helpfull if it helps,