The Pignose B100 is very light for a 100 watt all tube amp.
I've gotten warm tubey tone from a tube mic pre into a PA power amp, but I don't know if that'll get you what you want tone wise.
And the cab is more important than the head. No matter how great the tone from the head, if the cab can't reproduce that tone it's kind of pointless. Look at Audiokinesis, fEARful, fEARless, and Barefaced if you're in the UK. Big E is also looking very promising. And fdeck's HPF to maximize performance and maybe a good para EQ (should your head lack it) for tone shaping on a relatively flat cab.
Were it me, I'd get one of the boutique super cabs and one of the lightweight power amps (ideally with DSP and good input sensitivity). From there, get your hands on as many pre amps and pedals as you can til you get your tone. Buy used and you can sell for what you paid generally.