Best Amp & Pre-amp combo for under $2000 ???

Arcam, Audio Refinement, YBA used integrated.

"Best" is subjective. There are dozens of choices I would choose over the vast majority of Rotel gear I hav heard, but I highly suggest you audition everything you can in order to see what best fits your tastes and needes, and don't hesitate to buy and sell a few amps/preamps before settling.

The Musical Fidelity A3cr amp and preamp are a natural choice in your price range, both can be had for about $1600 to $1700 in total, maybe a little more or less, and will eat any Rotel setup alive. An Odyssey Stratos amp at around $900 used or $1300 new would also be a very good choice in affordable amps, as is the Belles 150A Hot Rod and Pass Aleph 3/30 for about $850, but all of these amps sound very different and personal preference will dictate what is right for you. There are many others worth mention but in your research and reading reviews on this site I'm sure you'll come across them. Also, don't underestimate what a good CD player and/or DAC will do, save some funds for the front end as well. Don't hesitate to audition some different speakers, too, while you are at it, you may amazed at what else is out there for only a litte more cash yet offers a huge step up in performance....

Kray: Unless you have a specific need for separates, I urge you to also given serious consideration to one of the better integrated amps available today. There are a number that are well worth considering, and unless you need an amp with a lot of power, the integrated amp actually gives you higher value for a given amount of money.

Among the integrateds you should consider are the Creek 5350SE, Bryston B-60, Perreau, and Musical Fidelity at the lower end of the price scale, and the Brinkmann at the upper end (you may be able to find one used for around $2000-2200).