WCT fronts and Neutral quad rears will get you closest. The only rub is that those quad rears are 80/20 foil whereas the K2.1 quad rears are flat.
You could try a set of Pivot quad rears (which are flat foiled) but the rear K2.1 rear quad set actually has a bit of rake to them.
An interesting combo might be the WCT fronts and the Scimitar rear quad fins. Those are a neutral, flat foiled template.
Quad surfboard fins - Komunity 2.1 Slater Futures - sporting goods - by owner - sale - craigslist
Good condition. Just riding thruster so never use them.
sfbay.craigslist.org