SET Tube Question

You shouldn't even need a sub with the Belles. Even a 3 watt 2A3 based amp will sound great on them. These are great speakers to try out very low power, warm sounding amps.
Ultimately, a pair of Cary 300B's would be awesome but starting with a pair of Decware 5 watt amp or Antique sound labs would be a really cheap way to get into this.
If you are new into tubes, stay away from vintage gear to avoid unneccessary problems.

Vintage Klipsch speakers together with SET amplification is a match made in heaven IMO. You are starting out at the top from my perspective. I think which SET amp you decide on (which tube type) may be determined by listening to the different types which is unfortunately not always easy to do since so few dealers seem to have a wide selection. Your musical tastes and expectations would be a good indicator of which direction to take, as well as your budget. A good middle ground is the 300B tube offering a bit more of a low end then the flea-powered options that emphasize the midrange at the expense of low end. Your Belle Klipsch can be driven with a match so power is not really an issue. As far as which amps to look at, I think George Wright's amps make a good pairing with Klipsch. See his offerings here. I also might look at Cary's SET offerings as they are plentiful and come up used at decent prices as well as being highly regarded. I have one of their preamps which is built like a tank and works well with my SET amps. Not sure about books, but there is plenty of info online by doing a bit of searching. A good starting place would be the SET ward over at AudioAsylum which is here. Also you may find further resources on the single driver speaker site here.

Hope that is of some help.

Good luck...I think you will be pleased with that combination if you do it right.

Marco

You may also want to try these sites. Each has a user forum and SET products for sale, both kit and assembled.

http://www.welbornelabs.com/

http://www.bottlehead.com/

I recently purchased a pair of Belle Klipsch speakers and I use the Wright Sound WPA3.5 Mono Blocks that use the 2A3 tube that Paul Klipsch is known to favor. There is also a forum at the Klipsch website. Ask those who "know". I have learned a great deal reading the information that flows in that forum. I have a rather large dedicated room, 20X30 with cathedral ceiling to 14ft. The WPA3.5s have more than enough power to fill my room. Congratulations and Enjoy!!