I've never been much of a video / surround sound person. I figure I probably already watch too much tv as it is and if I had surround sound/thx/7.1 or whatever the new thing in video sound is these days, it wouldn't be good, plus I didn't want to have to get all the gear that goes with it.
Over the years, I've always had tube amps with volume controls so I could use them as an integrated amp and then I have a little source selector box ($50) and phono preamp to allow me to play my tuner, cass, cd player, lp's and any other source.
A single ended amp sounds different from push pull. With the horns of the Klipsch, SE sounds more real, pure, and organic. An analogy would be this: SE is like a sweet delicious grapefruit, no sugar is needed because it tastes delicious all on its own. PP is a grapefruit with the extra sweetness of sugar added. SE is a beautiful naked woman, PP is a beautiful woman in a bikini. PP is more accentuated but with the immediacy of horn speakers, the SE amp sounds better, IMO. I prefer both SE and PP tube gear to solid state gear.
And the lower the power the better it usually sounds. Any tube can be made to run in SE mode, but the true 4 pin triode tubes (2a3, 300B, 45, 50, 10, 845 & 211) sound way better than other tubes. They will be more expensive too and the 845 and 211 will be of much higher power too. To keep costs down, I would look for a SE amp that doesn't use one of these tubes.
In the past, I've owned a 5 wpc 6BQ5 SE int run in pentode (a little higher power and better bass) and also a KT88 int that ran in both triode and pentode (5/15 wpc) and the triode was sweeter sounding. I now own a couple custom SE 45 amps and a custom 3E29 amp that I recently inherited and selling 2 of them as soon as I can get them looked at by a technician. I imagine they will all sound pretty spectacular as they were built by the chief amp designer from the old Lafayette Radio Corp.
Running your sources thru an NAD preamp will also degrade the sound as well. A source selector switchbox might just be the best remedy. Use it for your audio sources directly to the tube amp, and then when you want to do video, have the NAD preamp plugged into the switchbox too.