2015.5 duramax delete

Hey guys. I’m sure it’s been asked before but I can’t find anything from recently. What’s the best delete for a 2015.5 Chevy 3500 SRW currently available? I know a lot of companies got shut down in 2023. Also is it entirely necessary to change the up pipe and down pipe? I saw a kit from SPE labs that connects to existing downpipe with the 3 bolts, does an EGR/DPF/DEF/CCV delete and has a mini max V2 tuner for like $1350. It does say it doesn’t support the factory pyrometer/EGY probes, but I’m not entirely sure what that means to be honest haha (off to google after this post). Any info or user experience is appreciated.