Escients are great for their organizational interface but sonically they are nothing to write home about. B&W 800 series speakers are capable of resolving more detail than the Escient can deliver. I'd add a really nice DAC to bi-pass their analog output stage if you go with the RX1052. For example the PS Audio Digital Link III is really nice, some like the Benchmark DAC's I haven't heard them myself. The 1057 is a home theater piece, it also has a DAC built in, but a 1052 with a nice DAC will EASILY trounce it on music. The 1057 might be underpowered for 804S and certainly would be for 803S. I would say that the only reason to consider a 1057 is if you want to do home theater, otherwise you are paying a lot of money for stuff you aren't going to use. Including HDMI switching, surround decoding, a couple of amplifiers, digital crossovers, etc. It's about a $600 integrated (an Rotel RA1062 for example) with all the extra stuff that I mentioned.

It sounds like you're on the right track so far. B&W 804 or 803 with a Rotel RX1052 and the PS Audio Digital Link III would be a really, really nice first system.