Stereo Receivers from the past...

It appears the speakers are of moderate efficiency, but a low impedance load that varies a bit across the spectrum.  These speakers will require current and an amp that is stable into low impedance loads.  Listening space is of small to moderate size, so absolute power may not be an issue.

NAD receiver.  Monitor series, or the original 7200 (receiver version of the well regarded 3020 integrated amp).  At 40yrs old, have it restored before use.  While rated for 20wpc, it is capable of 80wpc+ in short bursts and can drive low impedance speakers without breaking a sweat.

Just about any McIntosh receiver if you want to go in that direction.   1500 is tube tuner and amp, with a SS preamp.  1700 is tube tuner, the rest SS, and all models from the 1900 forward are SS.

Early Marantz receivers are very well regarded, and have a nice warm sound with plenty of drive.   

Under the radar-  Heathkit AA-1500.  60wpc at 8ohm and almost doubles into 4ohm.  Very sensitive tuner section, quiet and clean preamp section.  Plenty of power and current.   Even the cleanest example will be 45yrs old, so it WILL need restoration.    I inherited one from my father (he built it), and I then used it through HS, College and early adulthood...about 20yrs of hard use before it needed service.   It drove a pair of AR3a and AR5 speakers to great effect.  The former is a demanding 4ohm load.

I don't know how it would stack up to the many other receivers mentioned in this thread, but I love my Rotel RX-855 for a budget receiver.  Nice pre-out maini-in feature than can be useful, built like a tank.  Rated at 50 WPC, but feels like more ...  

+1 for Marantz with a 2275 here. 

+1 for late 70's early 80's Sansui,  Luxman, Accuphase. for Japanese anyway. built like tanks very good parts and a very good rep. the Sansui AU series were stellar but prices are climbing fast in the used market. The higher end Luxmans are all good (up to 1985) and if you can find a Class A unit grab it if you can stand the heat they are stellar. All the Accuphase stuff is a great buy, maybe their earlier stuff is a little on the homely side but inside they are up there with the best. 

glen 

I’ve never owned a receiver, having been advised early on that separates were the way to go, but my 45+ years in the HiFi business has given me a lot of perspective. Some favorites: the Pioneers of 1974-5 (SX-737, 838, SX-750 and up), Sansui 7 and 8, Marantz 2250 and its kin, Yamaha CR-800, 840. IMO, you can keep Kenwood, although their integrateds were great, ditto the Sansui AU/TU. I sold all the Nak receivers except their first model. The ones with Nelson Pass circuitry are probably the best sounding mid-fi receivers of all. I disagree with whoever said they break...the first 55 wpc model maybe, but from the SR series on they were solid. H-K had reliability issues, but the 930 was a beast.