You really gotta be more specific. Do you really know what you want, or do you just know you want something with tubes in it? Mic or line? Input and output impedances required? Gain and output level required? Your request is way too vague, so far.
Tube amplifiers, balanced or unbalanced, can be done with transformers or without. It really depends on your requirements.
Look at the Metas and do some searches. Much has been posted here... Some people who've written very detailed posts in the past may not feel like doing it all over again, or doing the work of sorting through the info for you. But if you're more specific about your requirements, at least that'll make it easier for anyone who's trying to point you in the right direction.