Life after Rotel RX 1052

There are tons of good choices.  Couple things - the speakers you have are not the easiest to drive well. They have a minimum impedance of 3.45 ohms which means you do want an amp that is comfortably at 4 ohms. The 87.7dB SPL is efficient enough.

Especially if you listen to bass heavy music, I would want home theater type headroom.  Those speakers need 125w to deliver 105dB of volume at 10'.  That would be the power rating I would look for.  

IMO, the best value in your price range new would be Musical Fidelity.  The M5si is a darn nice integrated which will have enough headroom for the music you listen too and will be fine at 4 ohms.  I think it would be a clear step up.  I am an MF dealer and would be happy to work with you if you have interest.  

Roksan also makes amps in this price range that I think are excellent and would be worth your time considering.  The Cambridge Audio 851A is a nice unit.  

In used gear, you might find a Rogue Pharaoh in that range.  It is an awesome integrated.  I have had the Hydra which is the 100w power amp in the same family for years.. 

It is tough to beat Musical Fidelity and Rogue in terms of value. 

I am not a hug fan of using a separate preamp (especially a receiver) in this price range but in fairness, have no practical experience with the preamp stage in your unit and it might be just fine.  Personal taste and bias there,.  

Depending on your ears I would suggest testing out at home if Possible and no particular order the four below because they sounded good to me. I like a warmer sound and I am using a pre-amp, either a Rotel, or Parasound depending on what I listen too.

ArcamRotelParasoundUsed McIntosh
As the previous post mentioned, make sure the amp can handle the speakers.  Can you wait until you get the SFs?  There are a lot more you can try also, but these are ones I have worked with in that range.  But you could easily add 30 more that might work. I didn't personally like the Yamaha, or NAD stuff.  But that's my ears and different gear in a different room changes everything.

I used that receiver for about a year with a set of NHT SB3s. It worked well, but imho, was nothing special. I think it will be easy to improve on. I would not use the 1052 as a pre-amp. Either put it in your second system or sell it.

I am going to sound like a broken record. $299 for a closeout Schiit Saga or the new Schiit Saga + and $699 for a Schiit Vidar Amp. For $1,000, you will have a very nice sounding combo that comes with a 5 year warranty and you will have a hard, if not impossible time, beating for the same price used. Take the $1000 extra and use it on room treatments or put it in the bank.

In looking used, personally I would target newer Parasound equipment. Nice sounding, ability to drive moderately hard loads, and a good value. I say newer, because amps do age, and as their capacitors age, they change in sound. The only question is how much and how long it takes.

Maybe keeping the RX 1052 as my pre-amp could be an option?

No. Absolutely not. Do not make the huge mistake of underestimating the importance of a preamp in a stereo system. And let’s be clear here -- the preamp section in your receiver sucks. At your price level you’re best off with a good integrated stereo amp. The Hegel H160 is a great integrated that sonically pretty much shoots down the middle, has plenty of power for your speakers, and will trounce the performance of your Rotel on all levels. Here’s a nice one available here now in your price range...

https://www.audiogon.com/listings/lis9ffb9-hegel-h160-stereo-integrated-amplifier-dac-d-a-converter-....

Here’s a review of the H160 where it held its own in a system approaching $300k. Just think what it could do in your system.

http://www.theabsolutesound.com/articles/hegel-h160-integrated-amplifier-1/

Best of luck in your search.

Coming back to this a little (way) late, but know that it was because I took all the info / advice and went into a deep, dark tunnel for a while to make a decision. This was quite an education for me so thank you all for kickstarting that. 
During the search my budget had to be cut somewhat considerably. It looks like mcreyn's suggestion of a Schiit combo makes the most sense. (They earned another fanboy, for better or worse). 
The Hegel suggestion will stick down in my subconscious as my next move, but hopefully not soon. HOPEFULLY.

absolutlahmi

Another +vote for an Integrated amp. There are plenty of options in the demo/used marketplace. Back in the 2000's I enjoyed Rotel electronics as well. Keep us posted on your purchase decision.

Happy Listening!