There are a couple of integrated amps that I would consider for use with this speaker. The first would be the VAC Super Avatar, one of the all-time best sounding tube integrated amps made, IMO. Smooth, refined detailed sound that would get the best sound from any analog or digital based front end with a minimum of fuss and hassle. Easy to cable as well.
The other choice would be the Pathos Classic One Mk II, which is a great sounding tube/ss hybrid integrated at a very affordable price. Not quite in the same sonic league as the VAC, but at less than 1/2 the price, it would come very close for those on a budget. This integrated would have no problem driving the Auditors to very room filling levels, unless you happened to want to fill a gymnasium.