Next step suggestions, from Spendor SP100r ?

Hi all,
holidays are very "dangerous" from an audiophile point of view, because there is time to think more about your system and subsequent changes ;-)
So, in these holidays I started to think a way to make some evolution in my system, starting from speakers but not only, even if I'm satisfied for the actual sound.
My question is how to evolve the sound of Spendors SP100r (not r2) without loosing their superb musicality. In particular I wish a deeper and controlled bass, more punch, without loosing efficiency and SP-100r mids.
Now my taste of music is 80% Rock and Electronica, 19,99% Jazz and practically no Classical music, even if sometimes I like a good sounding system for this genre.
Starting to think about that, I have difficulties in creating a list of speakers to hear ;-) who can me help with some suggestions? Consider this a brainstorming exercise :-)
My system pictures and composition are in my profile, my listening room is 11m x 4,5m but I have some restrictions: speakers distance from the rear walls not more than 70cm, from side walls not more tahn 30cm., speakers not large more than 55cm due to my furniture shape. Listening point is around the middle of the room. The floor has an acoustic treatment.
Thanks in advance for the suggestions :-)
-Massimo
.Vitus Audio RI-100 amplifier
.Weiss 202 DAC
.TW Acoustic Raven One+ SME310 + Dynavector XX2mk2
.Audia Flight Phono preamp
http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1308315331&view