A friend of mine runs Hatton Performance, which is a general internet based modifications shop for all cars. He has been working in conjunction with a german coilover manfacturer to produce budget coilovers for the front and rear of cars that would normally have a seperate pigtail spring and shortened dampener.
A general description of them would be similar to that of the raceland coilover kit but with a rather short rear coilover. i am waiting on my kit for the astra which will hopefully be with me at the end of the month, but i can tell you a drop of 120mm all round will be available and the kit will retail for no more than £240.
As far as i am aware the only other full coilover kit for the astra g is the regal kit which is over £1k so this makes for the perfect budget alternative.
If people are interested in the kit please PM me with contact details which I will pass onto Hatton performance, a full review will be done once I have the kit.