Tubes for Primaluna DiaLogue Premium HP

Hello,

I am thinking of upgrading my tubes on my PrimaLuna Dialogue Premium HP. 

It already has The stock Prima Luna 12au7 preamp tubes and the 8 kt120’s. 

I am thinking of upgrading the 6 preamp tubes to Gold Lion ECC82 / B749 / 12AU7. 

And is there a recommended larger tubes for this amp? 

In general I year for a super wide soundstage, super forward presentation, sultry mids…

I hear that replacing the two gain tubes (?) with Mullard CV4003 has really good results… 

And I hear of Gold Lion Kt 77 (?) have terrific results for the large tubes?

Am running B&W 803 Nautilus speakers.

Thoughts?

Thank you!

Richard