Why are u against a Rotel Preamp? Because some of them( RC 1070) have few negative reviews? Since u have the RB 1080 the perfect handshake would only be a Rotel pre or if u have the budget a higher end preamp. I am in no way saying that the Rotel Pre s are great but IMO the RC 1082 is pretty decent and good VFM if bought abroad.
Please dont match it with a Nad or similar.
I had the RB 1080 for quite a while and also owned the RC 1070/RC 1082/ Nad C160 and the Rotels worked well with each other. Just before i sold the combo i tried the power amp with the Bryston BP 16 preamp and the much cheaper rotel pre sounded better. One is tweaked to match the other and its always safer to go for a pre/power of the same brand.
BTW do u have a dedicated 15 amp circuit? The Rotel power amp has no soft start and may cause the line to trip on power up.
B &W s 700 and 800 series may more costlay than Dali ikon6,i like dali6 than MA RS6