which tube?

i interested in getting into tubes. but not sure which tube amp to buy.

i listen to a lot of rock n roll, blues, jazz, some metal etc.

i already have a naim and musical fidelity setup for loud rock music.

what i am currently looking for is a system to hear at low or moderate volumes at night. what i want to listen at night is soft rock, blues, jazz etc. like nick drake's 'eight leaves left', simon and garfunkel, cooking with the miles davis quintet, thelonius monk's 'brilliant corners', Coltrane's 'lush life', buddy guy's 'a man and the blues' etc.

so i am not really looking for 'slam' or 'grunt'. and i want it to be more versatile than only playing 'a girl and a guitar' kind of music. and i don't particularly prefer it to sound like solid state - like kt88 is supposed to? i would rather prefer it to convey the magic of tubes.

so which tube based amp to go for - 300b, el84, kt88, el34 etc?

single ended or push and pull?

appreciate the insights.
Which speakers do you have?
If you're seriously considering SET amplifiers you must have an efficient easy to drive speaker or you'll never maximize the potential of the SET. You have to consider the two as an inseparable pair. If you do this then your chances for sucess and rewarding sound is very high.
I agree with Charles1dad and would add that IMO 2A3 and 300B SET amps (with appropriate speakers) are in their sweet spot in the conditions you describe.
Take a look at the thread going about tube amps and electrostats. I just posted a link to an article written by Keith Howard in 2007 which cogently discusses "EPDR" ratings and how EPDR stats can be used to predict how well a particular amp will perform when driving a specific speaker. I see no reason why the article wouldn't be applicable to SET amps.