Between those two I would as the owner of a pair of Haflers probably opt for the SAE. The Haflers could be bridged for 300 wpc but the will not want to drive a 4 Ohm load so it would not be a benefit for those speakers. Another option is the Haflers and biamping the 910s. This would use a crossover after the preamp outputs before the Haflers and sound pretty good.
Still leaning toward a fully working fully refreshed SAE.
I normally used only one channel of my Haflers, using both for stereo, each with one channel idle. Power supply and transformer only supplying signal for one channel made them more capable.