Which tires and spacers needed for x5 style 74 rims

[LeoProdigy]

Hello I am fresh brand new to forum and have done a moderate amount of research on this subject. I have a stock e39 (525i) with 225/45/16 and wanting to install x5 style 74 rims which would be 255/55/18. I know I would need a wheel hub adapter but am lost to how thick the adapter should be since the x5 is 30mm thicker and 10m taller.
Unidentified Variables: 1.) size spacer (or Even if spacers are needed)
2.)which size tire works best with my ride height and suspension set at stock?

In advance: to anyone who reads or responds you are amazing and any help I will blindly listen to

[tmvE39E53Z32TT]

The OEM 18" wheels for E39 (I use style37 as example): 18x8 ET20 fronts 235/40/18, 18x9 ET24 rears 265/35/18.
Style74 for X5 (E53) 18x8.5 ET48 all-around 255/55/18 tires

With those info, here are the problem:
#1. The tires will need to be replaced. Sidewall is too tall for your E39. You can do 255/35/18 all-around.
#2. E53 has 72.56mm hub-bored (normal bimmer size) while the E39 need wheels with 74.1mm hub-bored. So hub-bored isn't match. However, you can use hub-convert spacers to correct this problem. This is related to #3
#3. Need spacers to lower the offset of the wheels so they won't rub on the spring/strut when installed. Combined with #2 (hub-bored problem) you can get hub-convert spacers with at least 28mm thickness to bring the offset down to ET20. The thickest spacers I found when doing this is 20mm. So the adjusted offset will be 28mm. This will fit on your E39 fine.

[LeoProdigy]

So basically a 30mm hub converter and extended lug bolts will remedy this situation? Is this a set up you're familiar with? (If so is the converter harsh on the suspension?)