I really liked that 8 team structure you mentioned. And if possible, would be a much better fit for a TT.
Although unlikely, I was thinking you could still keep the names of your current Super Rugby teams. Am I right in thinking that fans are attached to the Super Rugby teams because that's what their province is attached to? And if a couple of provinces broke away from the Super Rugby team to set up a new Super Rugby team, then the fans of those provinces would follow the new Super Rugby team?
I think you'd definitely keep the Blues, Crusaders etc "brands" & that it wouldn't be too difficult to quickly establish new ones. The Pasifika team would have an instant fan-base, you only have to look at how the Tongan & Samoan communities got behind "our boys" at RWC 2011 & RLWC more recently.
For the BofP-based team you'd need outside money & players but I have no doubt that there's a substantial number of people who'd prefer a game in Tauranga or Rotorua every second week to one a season. Tasman Mako is also pre-existing & many in that region would argue that they contribute far more to the Crusaders than they get in return: again, a game in Nelson or Blenheim every second week v one a season in Nelson & maybe a pre-season one in Blenheim isn't that hard a sell.
I'm not suggesting that the buy-in would be instantaneously 100% (I didn't become a Mako supporter until I moved back to NZ & saw that they were a real footy team not some marketing dept fiction) but I do think there'd be a decent-sized base to begin with that you could grow over time. The biggest challenge would be managing expectations as there's no way Pasifika & Mako are going to be the Blues & Crusaders on day one, but the Blues & Crusaders aren't going to be what they were, either, so it'll all even out just at a slightly lower quality level.