Ok, before I get too deep over my head....

Simply put, my project I plan is using a USB shield with a BT dongle to connect to a PS3 controller.

At the same time I want to use HC-05's to connect two arduinos together.

Is this a dream or am I chasing down the rabbit hole?

Perhaps not too deep..
I understand it is possible to connect Arduino to a PS3 controller, and using a USB host shield plus dongle seems a fair way of doing it. Assuming that, the main thing is that my USB host shield communicates on SPI bus. I imagine they all do. The HC-05 is a serial device, so there is no clash between the two devices. On my shield, the serial pins 0,1 are pass through, again common practice, thereby facilitating painless connection to Bluetooth. The shield is by Keyes.