New McIntosh C8 Preamp | Tube Rolling

Hey guys!

A bit of a disclaimer, I'm a newbie on the Tube Rolling world xD

I would like to do tube rolling on my McIntosh C8, this is the new version recently released: https://www.mcintoshlabs.com/products/preamplifiers/C8

My question are:

1. The tubes are labeled V1, V2, V3, V4.
   Is there a way I can now which one of them will give me the biggest difference if I swap them?

   Mainly to know, which tube affects what part of the sound, see the thread below for sort of a reference:

   https://forums.stevehoffman.tv/threads/tube-positions-on-c-20.145897/

2. Any recommendations of tubes brands that mix well with McIntosh Pre-Amps? (NOS or New Stuff)

Any help would be greatly appreciated :)

Thanks!