Z3M H&R Coilovers - Failed and dumped oil! Advice please

[zmrjason]

Really appreciate some advice/help/guidance or whatever!

Well as per above really my front coilovers are 2 years old and have covered maybe 12K including 3 track days. They have burst their seals and are now literally useless.
Questions:
Can they be revalved?
Is it possible to buy 2 new front coilovers without buying the rears? Any idea on cost
Why would they do this?

It is worth noting in the 2 year period I have had the coilovers I have also gone through 2 sets of whiteline ARB drop links. Can anyone shine a light on what might be causing this as it does not seem to me to be reasonable wear and tear!
I do run larger brakes, swapped top mounts and 18" LM's with 245x35's.......

Also the car now lives with me in the SOuth of France which rather complicates things a little with suppliers and delivery etc. Apologies for the rather general non specific post I just need to try and pick peoples brain so this problem does not re-occur and so I can try to source relevant parts, get them to france and get them fitted (the easy part).

Thanks in advance.