Rotel and Arcam do NOT sound the same. Arcam and Creek are similar in that they are both very fast and detailed. I would not say they were warm but to me warm is almost a negative, I think of rolled off highs and fat bass. Rotel makes the music sound like the band is on Valuim or playing with a bad hang over in comparison. Honestly if you like Rotel then I would not recommend the Arcam or Creek however the few Creek's I've heard did give an empression they are slightly warmer.. Rotel had a pleasant delivery but made my cd's sound sluggish and lacked dynamics. I'm used to the slam of Krell and Arcam, some people aren't into that and that's fine, I just didn't want you to go on my recommendation and not be happy. NAD has gone through many phases over the years so you really have to know their product, one year may be a good run where the next they are under different management or ownership and the gear will be different. I always thought NAD presented a very thin sound. I really don't know of anything to recommend that would be a cheaper alternative to Rotel since I really don't gravitate in that direction. Maybe the Marantz you mentioned or a Yamaha. Adcom may work but I think would be out of your price range. Adcom would be somewhere between Rotel and Arcam, they are still fast but give a big bass sound.

I have emailed spearitsound on some things and they seem very knowledgeable. They have almost every high end line you can imagine. They do a lot of Ebay sales and have good standing. Although I haven't bought from them yet, I wouldn't be afraid to deal with them.

Even though your speakers are 4 ohm, I'd think they would still be easy to drive with such a high efficiency rating.