[Does the UPS have the isolation transformer integral to it?]
Yes
[Does it also have the circuit breakers integral?]
Yes, everything shown on the diagram is included, you only need to bring in the utility power source and the cables to the load.
[I only need one panel (computer loads) connected to a UPS. So, would I connect thru the UPS or have a transfer switch. I am assuming directly thru it.]
Then bring the cable from the panel originally destined to the computer loads to the UPS instead, and the output of the UPS to the loads.