The Cap-300T is a complete system with the compressor, condensor, dryer, everything. The IP-9100 is just the parts that go inside the cab. You would need your own compressor, condensor, and dryer.
Depending on what you already have and how handy you are, sourcing/installing those extra parts can be done fairly cheaply.
I also don't know anything about Regis engines, but if it is a standard SBC with a mechanical fan you should be good to go. You will want to maake sure you have a good shroud too ensure the airflow goes through the condensor/radiator but you would want that anyway.
