Depends what your looking for… darkvoice has that wetter very tube like sound and ta-10 is a hybrid but sounds a bit more solid state… can’t go wrong with either imo.
I don’t see why not but you’d need a special set of cables for that… darkvoice there only has rca ports in the back. Also, noticing you mentioned speakers… the darkvoice does not have a preamp port in the back like something such as liquid spark for speakers.