[madsry]

You've been offered a chance to have a custom preamp as well as custom tube monoblocks built to your spec.  You enjoy a bit of tube flavor, but love tubes especially for the dimensionality and the life they tend to infuse into the sound.  The gorgeous midrange and spacious highs don't hurt either!  Ideally, at least a little punch can remain in the bass department.  15-20 watts per can be enough (leaving a little room for SET amps), but no initial bias towards any particular implementation.  Bonus for using tubes that aren't exceedingly pricey or numerous, but still deliver the goods. 

Now to the design.  What tubes compliment do you gravitate towards and why?  What circuit design do you utilize and why? 

[thorman]

 I guess for me it would be Lamm Amp/Preamp Combo for me. Any of there products are to " Dream For " ...

[Docere]

You've been offered a chance to have a custom preamp as well as custom tube monoblocks built to your spec.  You enjoy a bit of tube flavor, but love tubes especially for the dimensionality and the life they tend to infuse into the sound.  The gorgeous midrange and spacious highs don't hurt either!  Ideally, at least a little punch can remain in the bass department.  15-20 watts per can be enough (leaving a little room for SET amps), but no initial bias towards any particular implementation.  Bonus for using tubes that aren't exceedingly pricey or numerous, but still deliver the goods. 

Now to the design.  What tubes compliment do you gravitate towards and why?  What circuit design do you utilize and why?

For that type musical presentation: well-designed all-DHT with well-chosen operating points, quality nanocrystalline core signal transformers, no feedback, and a well-designed power supply suited to the topology chosen; mild voicing with component selection. Unless driving speakers specifically designed for low/no-feedback SE amps, use push-pull outputs. Implement quality tubes conservatively and with care and they will last so long their cost will hardly matter; buy a spare set for peace of mind. If engaging a quality builder, be prepared to pay for it (both a warning and encouragement to pay a quality craftsperson/technician).

[FullRangeMan]

All requirements you mentioned match to the Lampizator GM70 amp and yet aré SET DHT. Tubes are under  $30 each at GSTUBES.COM and there are plenty of this tube in Rússia.

[Docere]

For clarity: FRM would be referring to the OP, not my post.

[Triode Pete]

No doubt BorderPatrol amps & preamp with 300B tubes, tremendous & accurate bass response due to phenomenal power supplies...

My $0.02,
Pete

[madsry]

Appreciating the replies so far...

What are everyone's thoughts about the value proposition between a custom build vs a retail product.  With tube circuits/implementations, wouldn't there be a much greater value with the custom build/clone?  Or am I underestimating something here...

[Tyson]

I think the value of a custom build is the chance to hear some good tubes that are off the beaten path. 

[FullRangeMan]

Appreciating the replies so far...

What are everyone's thoughts about the value proposition between a custom build vs a retail product.  With tube circuits/implementations, wouldn't there be a much greater value with the custom build/clone?  Or am I underestimating something here...

The vantage of a custom made to order amp is you can choose the best parts on crítical áreas as wiring, transformers and circuit.

[R_burke]

For the amps I would go with  Manley Mahi, but with upgraded high end components throughout, and Mullard EL84 tubes
https://www.manley.com/hifi/mahi