E53 4.8is Stereo upgrade starting in a few weeks

[ajacks8]

So, it sounds like crossovers can offset DSP requirements? Since I don't have JL crossovers laying around - would you recommend these for me? (x2?)

https://www.amazon.com/dp/B0036D1DQI..._t2_B003QQ67HA

Also, by utilizing crossovers...should I be fine with the MX280/4 amp? I'm still a little confused on impact of DSP concept...but I'm hoping that with Eonon head unit - I might have some flexibility?

Lastly, I've always kept an eye on this european seller's solution on eBay:

https://www.ebay.com/itm/BMW-X5-E53-...53.m1438.l2649

Seems like sourcing C2 level stuff on Amazon makes more sense than this kit of C1 level stuff...but I don't have experience with either that may be a bad assumption. Can anyone tell if the "mounting collars" included in the eBay kit come standard with what JL sells? If not - might getting those be worth the difference in performance/installation? Sorry for the naiveté...I'm used to just moving my old JL setup from vehicle to vehicle...but I recently retired that setup after 17yrs and want to custom match a new system to my new rig! Thanks for any insight.