It sounds like you have a good plan for the use of the equipment and that it has multiple uses.

I use to also use ENO Slapstrap, until I watched some videos on how easy it was to make and use whoppie slings, and now I wont go back.

The people here just recommend things from their personal experiences. Like others have said your the one that is going to be using it and the one that has to be completely comfortable with the setup.