Roof rack help - Add cab crossbar with camper shell rack?

Sorry for another rack post, but I wasn't able to find what I was looking for after searching.

I'm installing a Rhino Rack system on my campershell, but I'm not sure it'll be adequate to carry my paddleboard (and my future canoe). I'm thinking I might need a 3rd crossbar up front mounted on the cab. I really don't want to install anything permanent on the cab, but I think they have products that are removable that just attach to the rain gutters or window frames. Can anyone steer my in the right direction for a front crossbar? I'm assuming Rhino Rack might have something and it'd probably be best to match. I'm sure I'll find it with a bit more searching, but if anyone has any recommendations or tips I'm all ears.

I don't know much about roof racks - never had one on any of my vehicles, so any input is welcome!

Thankle, OSC