If you're looking into solid state used gear, and are looking at Threshold, you want to look at the older T-100/200/400 series stuff! Actually,those speakers (I like) would do better with at least T200 or above! They run a good percentage in to class a compared to everthing else in that line. You might want to do a tube preamp on top to ad a bit of tube majic with the Proac's..I think you'd like th combo. That way you get the best of both worlds, with the control and slam of solid state!
Good luck
Good luck