Class D or Hybrid Amp for Fritz Rev 7 speakers

I am a long-time member but very seldom post. However, I value the expertise here as I have not bought a lot of audio equipment in my day. My goal in 2014 is to upgrade my power amp to hopefully get more detail, a better midrange, and better soundstage. After upgrading the amp, my plan is to upgrade the pre-amp in 2015.

I had some great recommendations on potential tube amps but when I started reading the manuals, I realized that I don’t have the rack space to suit a higher powered tube amp. It seems like there is a lot of discussion here on Class D so I thought I would ask for comments/help.

My current system consists of MacMini/Rega DAC/Acurus RL11 preamp/Acurus A250 power amp/Fritz Rev 7 speakers. The Rev 7s are 4 ohm, 89 db sensitivity. I plan to keep these for a long time so want an amp to match. The Acurus equipment was modded a couple years ago.

My budget is approximately $2K used or new. As of now, my plan is to try a hybrid tube amp (Rogue or Audio by Van Alstine) or Class D amp. If I don’t get one of the hybrids, I would be intrigued by Class D amps such as Channel Islands, W4S, and Bel Canto.

One criteria is that they would have to be compatible with a tube pre-amp as I wan tto try tubes somewhere in my system. In 2015, I plan to upgrade the pre-amp. I have not heard Class D or tubes extensively so I don’t have a strong inclination. However, it seems that I could put together a nice combination using a class D or hybrid with a tube preamp.

Given my budget and system, are there any obvious combinations that you would recommend? Thanks in advance for any comments.
If you look to demo a class D; please check out the NewClear digital amp; it is very well built, a bargain and sounds fantastic. This is one of the very few Class D amps I'd ever consider and it does mate with tubes. Here's a link:
I am using a class d amp with a tube pre and it is by far the best combination I have owned so far. Previous amps from Marsh, Odyssey, Adcom, B&K, Qucksilver, and a few others were easily bested by the class d amp. My speakers are Speaker Art Super Clef and Proac Response 2.5's.
If you have an interest in building an amp, I was able to build the Ncore 400's with zero prior experience-had to learn how to solder on YouTube. Out went the B&K mono blocs, the Aragon 8008BB, and the Classe blocs. Not even close right out of the gate. Planned on long term comparisons but have never wanted to take the Ncore's out.
Thanks for the comments. On paper, a Class D power amp and tube preamp makes a lot of sense. I love the idea of building one but am not sure about the time commitment and would also be learning to solder on YouTube!