I have the Arnott replacements or new design in the front and Arnott rebuilts in the back, before you start replacing struts, you need to listen closely for air leaks, shortly after one of my rears went off like a shotgun [obvious] the front was sagging evenly at night. fronts were leaking from the top seals, but even after replacing them I still had a valve body leak apparently. This extra run time for the compressor took that out as well. luckily I didn't have any line leaks so 300 for compressor,350 for valve body 300 each for rears and 350 each for the new Arnott design fronts. six weeks later I'm starting to get a height sensor issue I think, so chasing that down now. so again diagnose as best you can before throwing 3k at the problem, but be prepared for renovating the whole system.
I got the Arnott's direct with warranty and the compressor and valve body from Eeuroparts because they were cheapest on OEM parts. others have purchased OEM's from elsewhere with good luck and pricing, so you'll want to check that out