Hi, that sounds great. The first question for choice of SDK is what you want to create? There’s Unity, WFP and UWP SDKs available.
The UWP is actually built into Windows 10 and Visual Studio 2019 (no external downloads necessary), so just to get a feel for the eye tracker I would recommend https://docs.microsoft.com/en-us/windows/uwp/design/input/gaze-interactions that features some copy and paste code complete with a downloadable sample in the end of page.
For the specific error that you are hitting, I suspect a 32/64 bit mismatch in dlls and the binaries produced, you can try to change the bitness from 32 to 64 bit or vice versa. This is a bit of a problem sometimes with our native dlls.