Help - ABS Modulator/Pump compatibility ?

Can anyone tell me which vehicles had the same modulator assembly fitted (or are they all different), I'm looking to maybe purchase a 'spare' unit to mess about with or just to refurb and keep on the shelf for future use and have seen many on Ebay that look to be the same (but could be different in some way).

So, looking for a semi-definitive list of vehicles that may have a compatible ABS pump/modulator for my 1999 Disco II (petrol V8).

Thanks
Mike

What i-m sure now is that u need a WABCO "D" unit. I'm at work now but later i'll tell u on what cars was this one used cos i have a list a back home.

Here is the list for WABCO D :
Defender
Defender (L316) (2007 -)
Freelander 1
Discovery II
Range Rover (P38a)

Though there are Freelander 1's with MK20 / MK25 modulator and P38's with Wabco C ... so go for WABCO D, the only one used on D2...and i dunno the difference between these units

Hope this helps