Of the 3 you list, I like the Rowland the best. I don't know why you prefer the same brand though. There are some strong contenders that specialize in one aspect. Amps for instance, I'd recommend a pair of Clayton Audio M-100 monoblocks. McCormack, as mentioned by Stehno, also makes great amps. Neither McCormack or Clayton has a strong preamp though. Klyne makes some of the best solid state preamps out there, but no amps. I personally don't think you could do better than a pair of Clayton M-100's amps with a Klyne 7LX-3.5b preamp at the $6K price point.
Regards,
John