bought a 2017 kw w900l

[cheepjeep85]

ok, well, where to start?

what would you consider the most important on that list? and yes i do plan on doing a de-mandate, but keeping the egr, it seems like i read on here that you should on these engines. Unless of course that is untrue and proper tuning can be achieved that won't cause damage at a later date. Would really like to do away with both, but do it the right way.

Would you buy the knock off cummins inline on ebay or one of the several knockoff nexiq usb links? Do they have any issues?