System B is quite good electronics. I would say the best things you can do for less than $1K is buy speakers and if you are serious about your video a sub that integrates well for movies...that is serious fun when the action flicks start rolling!!! Note you will have to work hard for musical integration. The older s/hand Velodyne works pretty well for a few hundred.
As for speakers, if you wish to stick with bookshelves, i would say: Celestion SL600si, SL700si, (both shielded for video purposes), Totem Acoustics...all good musical speakers (Totem have superior bass, Celestion have magical midrange). All these are available second hand if you search for a few hundred.
if you dont wish to do sub, $1K used will get you pretty far. PSB makes good clean speakers, SFaber has some older floorstanders which are quite good. Epos...the list goes on.
good luck and pls keep us posted.
