tube amp or int for digital audio?

I have a classic Marantz 2250b receiver hooked up to my iMAC. It is driving some Energy RC-minis as our bedroom system. We use it for playing CDs, iTunes, internet radio, and watching movies.

I'm thinking of replacing the Marantz with a tube amp. I just want to try tubes! We listen to jazz, classical, new age, and some rock ... modest output levels.
Something >20 w/ch should work for us.

Since it's pretty much a 1-input system, should I go for a tube amp or an integrated-amp?

I love the look of Jolida, Cayin, Prima Luna, etc ... but have yet to listen to any.

should I go for a tube amp or an integrated-amp?

I don't really understand what you are asking.An integrated amp can be tube,solid state or hybrid(combination of both).Maybe you mean a tube power amp or a tube integrated?Then again,maybe I'm just a dumb ass!!
When we use my wife Ipod through my tube Primaluna Int Amp it sounds great. When we hook it up to a friend SS receiver not so good.
Grinnell, which PL do you have?

You want an integrated amp so you are not using the volume control in the mac to adjust the system volume.
Is it best to keep the iTunes volume maxed out ... and use an int for volume control?
That question (volume control) is debatable like everything else. Most will tell you yes (use a preamp) but I used the Itunes volume on a mac with several different DACs w/o any noticeable difference in performance. Even now with a preamp in my setup I still use my Ipod touch to "fine tune" the volume instead of messing with my preamp volume. My setup is fairly resolving and I can't really tell a difference.
We have a PL2, easy to use, low maintainance
Well, went ahead and ordered a Cayin A-50T! Can't wait for iti to show up.