Tube amp Questions

So, I’m leaing towards the Rogue Pharaoh with the hybrid tube /ss design.

However, are there more powerful options out there in the Hybrid realm of amps… say 250 to 300 watts/channel into 8 ohms?

Check out Audio By Van Alstine, one of their Fet Valve Hybrid Amplifiers. My speakers' rated sensitivity are similar to yours and I had an earlier edition Fet Valve and liked it very much. A little tube flavor with lots of power. Very well built, sounds great, lots of power, reasonably priced, built in USA (if that matters to you), and terrific customer support. I would still own it today had I not pursued an all-tube power amplifier.

http://http//www.avahifi.com/products/power-amplifiers/hybrid-amplifiers

So The Van Alstine 600-R is an Amp not an Intergrated.

If I went that way could I use my HK990 as a Pre amp?  And how would I hook that up? 

Would that be going the opposite way using a solid state pre amp with a tube amp? As I understand it's best to use a tube pre amp with a Solid State Amp…. right?

Or could I use my Oppo 105D as a preamp? I have read where that might not be the best thing to do. 

To clarify my previous question… Are there more Powerful Hybrid Integrated options to the Rogue Pharaoh Hybrid Integrated out there? 

Correct, the 600-R is not an integrated amp, sorry, my bad.
Many integrated amps have pre amp outputs (line level) to connect to power amps - not sure if yours does but would be surprised if it does not.
If it does you could connect your current integrated pre amp outputs to a separate power amp (solid state, hybrid, or tube). That is what I did when I purchased my AVA hybrid Fet Valve power amp - connected my existing pre amp outputs to it.
Some people prefer solid state pre amps with hybrid or tube power amps. There is no "best" or right way as far as that goes - that is up to your brain/ears. Assuming the gear matches up properly (input/output impedances).
Last I knew AVA would allow a trial period so you could try it out to see if you like it. You would be responsible for the cost of return shipping only if you disliked the sound.
I "progressed" from my hybrid integrated; to using it as a pre amp with AVA Fet Valve hybrid amp; to replacing the integrated with an all-tube pre amp; and finally replacing the Fet Valve power amp with an all-tube power amp. Each step along the way I discovered I wanted more and more of what proper tubes can do for the sound. So much that I ended up with all tube gear.
However you go, good luck in your pursuit of audio perfection!

Went away from the tubes and bought a Coda CSIB integrated. 

It just arrived but due to my work schedule I won't be able to get it into my system until after Christmas.

Thanks to all of you who shared your knowledge and took time out of your life's to help guide me.

Happy Holidays!