LAD shocks only OEM. Also the springs are different for the LAD system. They are solfter. If you want to replace the LAD, you have to buy an self levelling elimination kit from www.bavauto.com
That site even has an instruction on how to do that. But only this will set you back about 200 $.
I assume you do not have EDC. Otherwise it will be even more complicated.
Front is no problem. You can buy whatever you want. But I would buy new parts for this, not used ones.
Vinesparts is selling a kit now
http://cgi.ebay.com/ebaymotors/BMW-F...spagenameZWDVW
The say all parts are made in Germany. That is not the insurance that the product is good. There are many smaller makers, and even some bigger ones have not the quality like Lemfoerder or Meyle.
But quality is more expensive, as you know.
And made in Germany is basically no longer allowed to say as far as I know, it should be mentioned made in the EU.
And those products can come from any of the cheaper producing countries in the EU, also the newcomers to the EU.