First Hand Experience?

wcc10, I don't have any experience with Rotel, but I do have it with Parasound.  I don't think you will find any issues with 2-channel performance with either the A23 or A21.  There are plenty of reviews on the net and testimonials here and on other forums to support their capabilities.

I'm curious about the THX certifications. Does that get in the way of a strictly music set up? In other words, would I be paying for something I don't want and, as it is designed for home theater also, is it an infringement on my needs?

Just because it its THX certified, doesn't mean it is designed for HT use only.  And your not paying for it.  Parasound is by paying THX for the certification.  So consider this a bonus.

I have had Parasound THX certified components in the past and it is excellent, high value gear for 2 channel application.  I wouldn't hesitate getting another HALO amp.

Thanks for the input on the Parasound amps. I have had my eye on them, but wasn't sure what to think. Will read any reviews I can find.

Since you are going to use your Yamaha as a separate amp or pre I would purchase the pre 1st as it would add the most toward an upgrade. I, and several others on this forum, truly enjoy the tube pre/SS amp combo. You then have a choice as to improving your digital front end or go the TT phonostage route as sources. Do you have an budget estimate you are willing to spend on this system?

Now, if the Yamaha amp doesn’t drive you speakers to the extent you want, then buy the amp 1st. Regarding amps, I would go with a Parasound or Odyssey amp (lean toward this somewhat more). I own a Jolida Fusion pre that I think is great value (at$1350).

I take it that you currently have a CD player. If so does it have digital out? ItIf so it could be used as a transport with an external DAC. The DAC could also support a computer as a server. 

Once you get to considering the TT you need to consider the TT/cartridge/phonostate as a unit to obtain the best synergy. 

Again consider this an enjoyable journey. Keep the music 1st, and upgrade components as a means to this end.

Somewhere along the line you'll need to consider the impedance match between whatever power and pre amps you get; so you might want to decide which of each you ultimately will get regardless of timing. Another consideration might be to go the integrated amp route.