I'm sure these are self contained self levelling shockers, Volvo have used this type since the 7 series estates on higher spec models, they've always been an eye watering price, you might find new Boge self levellers via a good motor factor for a better price...i would not buy elcheapo unheard of makes and make double sure aftermarket are self levellers, dirt cheap they won't be.

Before you buy them it might be worth trying to obtain a set from a scrapper dpending on the reason for scrapping obviously, i've managed to find them for 7/9 series before now, so with a bit, no lots of luck you might find a set for a decent price, obviously you'll have to judge their condition as best you can...you have nothing to lose by looking...if you find a good set do the lottery that week and remember me..;)

They were a doddle to fit on the older cars and from your labour quote they must still be quite straightforward...tracking should be unaffected but no guaranatees..

Try these people I have used them loads of times and always had good service.

They do many self levelling replacement shocks and springs

http://www.mad-springs.com/

They look like standard shockers to me, without self levelling action, too thin from memory.

Probably not interchangeable unless you change the springs too...the self levellers during use pressurise themselves and the springs used with them are softer, you get the benefit of excellent load carrying whilst maintaining a softer ride unladen.

Fit non self levelling dampers with the wrong springs and the car will be too low and undersprung to boot.

My opinion only.