@dietMcar, for the suspension work, are you DIY or having a shop do it? suspension work can cost a decent amount so i think it's important to get it somewhat correct on this attempt. i understand about low budget but the initial savings "cheaping out" may end up costing you more in the long run and this can be applied to other mods and things in life as well.
i've read enough problems with BC on this platform and think you'd end up regretting these, just my personal opinion on BC for this platform.
i have/had different coils on other cars and between adjusting the corner heights, preload, compression and or rebound, creaking and clunking, i find it to be annoying continually f'king around with'em. maybe it's just me, but i read about others with the same issues and it doesn't matter if the coils were cheap or expensive.
fyi, there's been more than a few members that have had issues when lowering x-drives greater than 1.5"(38mm). as you lower, the front axle's geometry and forces on it change and some have had the axle fail by shear. the axle also starts to unseat from the differential as you lower and some have had the axles pop out.
while some have lowered x-drives more than 1.5" without issue, i've read enough posts where problems arose from lowering an x-drive too much. the link below is a thread where they determined what the max lowering should be. i'd follow the advice from such thread and not lower an x-drive more than 1.5" or 38mm.
https://f30.bimmerpost.com/forums/sh...1514736&page=2
i'd "buy once cry once" and get eibach pro-kit springs, F80 bumpstops and Bilstein B4 damptronic(if you can find them)...OR
Eibach, F80 bumps, Koni SA and edc delete, set+forget+cry less...OR
KW street comfort or V1 with edc delete for coils, 1.5" max for x-drive.
get new strut mounts with all of these and new spring seats and dust protectors if changing dampers.