Depends? Do you want it to taste like mint or taste like bubblegum?
That's like asking what strain to use for a 100% sacchromyces beer.
What sort of beer do you want to make? I don't think the main WL or Wyeast stuff is well suited to primary, but someone you know may or may not be getting some other brett strains if they ever get home from watching Mel Brooks movies….
I've only done a few all brett beers and it hasn't been my thing. The beers I made with WLP 645 Brett C were quite tart and not what I expected. I might have sent you one, I can't remember. First one actually turned out well enough I made it again, but when I looked into it Chad Yakobson found pichia and lacto in 645. I've also used some cantillon isolated stuff for primary and ended up adding dregs to it as the result of the brett primary was oddly perfumey.
I like brett is better for mixed fermentations or as a bottling strain, depending on what I'm looking for.