If I was looking for a used integrated amplifier in the $1500 price range the Belles Aria would be on my short list. It delivers 75wpc into 8ohms. My spearers are easy to drive however.
I haven't looked extensively but have not found the Aria spec for 4ohms. Also not familiar with your speakers. Question is how much the speaker impedance drops below 4ohms.
Not to over push the Rogue Sphinx V3, but there is a Stereophile review which includes a measurement section providing detailed account of this amplifier.
Both Belles and Rogue are good companies to deal with.