Which knock unit will be the best, rotary 13b engine

Hello guys i have a buddy of mine building a 2 rotor 13b FD3S Rx7 with twin high flow gcg turbos, using a Motec M84 and pdm unit, he is wondering if is better to use any knock control unit or nothing, he will use mainly Sunoco fuel, what you recommend for him, maybe Plex tuning knock monitor or any suggestions?

Thanks

Honestly with a rotary engine I'm less inclined to suggest that knock detection is worthwhile. The simple reality is that unless you're running some special apex seals, knock will very quickly destroy the engine. In other words, you're going to know if the engine has suffered from knock without the benefit of knock detection equipment.