Think I want a tube system?

For an excellent tube set-up a Leben Integrated tube amp would be a good start, although there are other fine integrated tube amps. Along with a relatively easy to drive speaker system, such as Harbeth, Devore, Vaughn (direct-buy), Coincident Technologies (direct buy), and you would have a killer system. If you get a good cd or sacd/cd player, or even a universal player would help, as would a good turntable and cartridge, if you are interested in getting into vinyl.

Of course, everything depends on your budget, so in order to give you better direction, that information would be necessary.

I am firmly in the SS power, tube pre camp. I dont believe I have heard that onkyo model, but they built it forever and it gets a lot of good press. If your speakers need that kind of grunt, I think you would be dissappointed going to an integrated, and high power tube amps can chew up expensive tubes. So try a tube pre for sure, then the question becomes how much do you want to spend and does it need to have a phono stage or would you do that later and separate. Also some caution is advised in having a one box pre with an onboard MC phono stage, they can be noisy.

Also consider a tube cdp.

Most of the new vinyl these days is recorded digitally but there are still some artists and labels dedicated to true analogue recording. On the other hand there's a ton of ways to buy used vinyl. I used to sneer at thrift store and flea market vinyl but I learned that a lot of the records were in nicer shape than a lot of my own and have found lots of good vinyl for a buck or less. They key is dropping in on a day when the right collection has been donated. I have probably bought somewhere around 1300 used lps in the past few years and a lot of them wont make their way to my TT until I retire likely. Happy retirement!

I think your speaker choice might be the determining factor as to whether or not a tube amp is the way to go.

You will find most of the tube sound comes from the power amp.

Hifihvn, I disagree with you. I think that the preamp is a MAJOR factor in where your sound comes from. Get the preamp wrong and the rest is history.
BUT with the right preamp and the wrong amp, well you may get an acceptable sound. IMHO, a good tube preamp is a very good building block in which to start.