Are you looking for bookshelf or floor (big) speakers? I have a 5000 at my mom's house setup with a pair of Infinity SM82 2 way bookshelf system from the earliy-mid 90's. Sounds really good, but is in in a large room 28'x24' with a 13' vaulted ceiling, drywall over 2x8 frame on three walls and ceiling, fourth wall is brick, with wall to wall carpet.
They sit about 36" off the floor atop built in wood bookshelves on either side of a full brick fireplace chimney. Probably not ideal placement height wise, but then it isn't a serious listening room either. When it gets cranked - rather than background music as it is used for 90% of the time - it can certainly leave one impressed.
The speakers are decent, but nothing spectacular IMHO, and I think the room plays a large role in how good the setup sounds, as well as the sonic signature of the 5000 (the 4000 will be identical, just at less max output power). The low end is exceptional, for a 8" two way and the acoustic coupling effect is clearly at work.
At my house, I use almost entirely Sansui speakers of various models - and like them - but most here will likely advise against that in favor of other newer, better regarded speaker designs.
I do have a pair of Cerwin Vega 211R 12" 3 way floor speakers (these have a rectangular horn midrange on the rear of the cabinet that fires slightly upward at the wall behind the speaker cabinet for an ambient effect) that I really like, but they are early 70's vintage and a tough model to find for sale.
I did woofer refoaming and crossover rebuilds on them years ago, and replaced the grille cloth. Very efficient (I.e.loud on minimal input power) and pretty bold and "in your face" so again, probably not to the taste of many. These predated the era where CV became straight-up rock and roll house party speakers, so a little more refined but still a bit brash. They sound great (to me) with a cap coupled amp like a 4000/5000, or just about anything else I've used with them.
