Mike:
I've got a few minutes and will respond substantively to your questions.
Rotel is very respectable for the money, but has some mid-fi "grain" in the mids and highs. The Bryston sounds better in most systems and has great resale value due to its twenty-year transferrible warranty. It is not as powerful as its wattage rating suggests, however, as its power supplies are an obvious reflection of its price point. On the whole, however, the Bryston is better.
The Audio Research LS-3 preamp pairs very well with the 4B-ST. One of my dealers swore by the combo, and, after having owned it and moved on to much higher end equipment, I really can admire what that combo does at its price point. LS-3's tend to go for $550-$650 used.
If, however, I were getting into the game on your budget and wanted the very best sounding system I could assemble (soundstages really well, is highly resolving, is dynamic, and most importantly, is natural-sounding, i.e., sounds like live music), I would buy a pair of Meadlowlark Heron speakers (the "i" version) and a Sonic Frontiers Power 1 tube amp. The combo is supurb, and used prices on both are very low because both companies folded. That should not be offputting, however, because the Power 1 is really well built and won't break, and even if it did, PartsConnexion, which is owned by the principals of Sonic Frontiers, services all Sonic Frontiers gear. The Power 1 is constructed with the same types of parts as the $10k Power 3, but now goes for $1,000-$1,100 because people just don't know what these amps are. Meadowlark was a superb speaker builder and they are very serviceable in the event there would ever be a problem (in this regard, it really should be said that most warranties in high-end audio are nothing but a wish given the incredibly high failure rate of audio companies).
There are a number of options for preamp to mate with a Power 1, depending upon whether you need a remote, phono capability, etc.
Cabling is a complex question that would require additional information from you about your source components, listening room, etc.
There are an almost infinite number of possible combinations you could choose, but if you value naturalness and bang for the buck, the above suggestion is, I respectfully submit, a very good one.