Just wanted to share the basics on what I used for my recent build. I've only had it out once but it ran great, just 100 rounds but no issues whatsoever.

Digital AR Products stripped upper
Sprinta Blem 9mm bolt
KAK Mag Block in an anderson lower
KAK extended buffer
16" Stainless Wilson barrel from JSE
9mm flash hider from Delta Team Tactical
PSA Metalform mags

Currently I just have a cheap handguard and carry handle sights but this thing shoots so nice I'll probably put something nicer on it.

Hope this helps someone in the future with any compatibility concerns, I had a tough time finding info on some of these less common brands.

Any pictures? Is the KAK block bottom type or the top load?