Cheapest 1080P 60FPS Capture card, External or Internal?

The title says all, I need the cheapest capture card for PC gaming to capture at 1080P and 60 FPS, with no extra load on my CPU or GPU.

yeah I have been looking around like crazy but got just too tired of it, so I am asking here hoping to get some tips on what's good and what is bad.
I dont care if it is external or internal for as long as it gets the job done, but externals are better in the sense that they are modular and mobile.