You can use low polygon vanilla meshes as bjornk pointed out, start from scratch and torture yourself. Or, you can use high polygon meshes that I linked. That way you have half the work done since you wont have to redo body sliders for BodySlide. You "just" have to add UUNP sliders which is still quite a project. And as I mentioned before, that will be a lot easier with high polygon meshes for obvious reasons. BTW, some 7b thigh and calf sliders are already there too which can also be used for various UUNP body types. Also, there is few known bugs that you should probably take a look at for your conversion. With that said, naturally, the choice is yours and Godspeed.