The consumer (original, free) version of Google Voice and the new, G Suite version of Google Voice are not compatible with each other. That means, for now, no number transfers between the two, and no, you cannot use consumer OBiTALK devices on the G Suite Google Voice.
Consumer Google Voice works with OBi 2xx, 1xxx and 2xxx products.
G Suite Google Voice only works with Poly VVX 150, 250, 350 and 450 IP phones.