Speakers for 2nd System!

A used pair of Audio Note AN-Js would work or a new or used pair of AN-Ks. Both would pair very well with your Leben.

@lalitk your going to have a VERY hard time finding everything on your want list..
 The only speakers that come to my mind offering sensitivity that high & half way decent bass are Klipsch & no one would call them good looking or hi end sounding..Speakers like the Audio Note @ 11"/13" wide are not what I consider a small footprint..There is the Devore Micro but limited bass & the Baby has good bass but @ 14.75" wide the footprint isn’t small..
 Odeon Germany makes a really nice looking stand mount & small footprint floorstander with decent bass but only a 90/91 db.sensitivity with true 8 ohm load..
 PMC Audio also makes some highly regarded stand mounted speakers but again only 90/91 db.efficiency @ 8 ohms...
 As mentioned already,they’re are smaller stand mounted speakers from Spendor,Harbeth & ProAc that are an easy 8 ohm load but efficiency is low..

I am using ATC SCM7's in my similar sized office, with 2 10" subs in a 2.2 configuration.   In this same room I've had Jamo, ELAC, Klipsch and KEF, and the ATC's are just so much more balanced.

If you plan to listen at low volume levels, high sensitivity speakers make sense but the trade-off is that it's very difficult to get low bass out of a high sensitivity speaker. Not impossible, but a real challenge to the designer. This is one reason why people with these types of speakers utilize subwoofers. Finding a speaker that is aesthetically pleasing, sensitive, has a small footprint and decent bass could be a problem. Good luck!

Here ya go, outstanding and can be bi amped.

https://tmraudio.com/speakers/bookshelf-speakers-monitors/legacy-calibre-xd-active-bookshelf-speakers-rosewood-pair-w-grilles-open-box/