Where to get started CM871 electronics

[HayMafia]

Hey everyone I’m new to this forum and have done a fair bit of reading and research and found this might be the one place to be. Me and my brother have recently became owner operators and have recently purchased a 2008 Pete with a isx15 cm871 cpl2733. I was wondering if anyone has a good link or know where to get a good working Cummins inline adapter I think I need a 6 or 7 or if cheap amazon ones do the trick or do I have to drop a wad on a genuine one so we can do our own maintenance and diag. I have other questions to find some other right ups and links to deregulation but I don’t want to get too off topic.