Speaker configuration Marantz 2270


I just received a Marantz MIJ 2270 from the late 70's. Looking for speaker opinions. I tested the unit on a pair of very cheap pair of bookshelf speakers. Granted the speakers were terrible, but I could tell the system could benefit from a sub; or a full range tower with bass speaker.

I am working within a budget of about 400-650ish. My experience with high end stereo equipment is limited, but am familiar with live speaker gear. I like the punch you can get from monitors, but have to keep in mind I would need a speaker that would like a lower powered signal being I'm working with 70 watts per channel, another reason to look at smaller
speakers.

In doing a search I noticed many people felt a sub of some sort is needed. I have found a few older passive subs with smaller drivers that had decent specs. I would like to entertain a passive sub as to get more the Marantz sound versus a powered sub. I would be concerned in blending
two set of speakers not knowing if I would need a crossover or not.

Being i am a newb I may be completely off base with my assumptions.
What suggestions could any of you provide me for my quest?

Thank you in advance
ricplaya
I paired my Marantz 2270 with Klipsch KG4's and it seemed like a perfect match. The KG4's are easily powered by the 2270. The KG4's pump out some serious volume with no distortion when the volume knob is about half way up.
I decided on a pair of ADS L570's

At first I wasn't quite sure what all the fuss was about. After a while of listening these speakers I started to lime them a lot more. They are very uncoloured and flat.. Takes a little getting use to. Great for jazz, classical. Lacks a little warmth for rock and I think it needs subs to add some booty.
Just picked up some kg 4's

Have the ads L 570's stacked on top tweeter to horn. Does sound a little shrill on some very high notes, overall really enjoying this set up. Will crank it up more tomorrow to hear the difference at higher volumes.