The club has done a group buy of powercoil springs and i think Payne has one spare set of 50mm lowering springs. You honestly dont want to go lower as it becomes to much of a hassle.
Depending on your budget you can do any of the following
1) KYB shocks - £160 roughly with powercoil springs - £100
2) Koni Adjustables - £280 roughly with powercoil springs - £100
3) Coilovers from D2 racing - £600 roughly (will find link)
4) Bilstein Group N spec road/gravel dampers - £800 with powercoil spring - £100
The coilovers are the best option but as of yet i have not found anyone that owns a set to give me a honest opinion about how they perform.
-KYB's can be bought from most motorfactors and their is a link on here somewere for a place that sells them for a reasonable price.
- Koni's are avaliable from a wide variety of places, although i would recommend Demon Tweeks (shameless plug) as they will have them to your door next day or the day after. (becoming a offical member allows you to save 10% on all parts bought from Demon Tweeks with membership starting from a tenner)
- Bilsteins are expensive but you will never want anything else again. If your interested send me a PM as i can source you some.
Their are other springs avaliable but they only lower upto 40mm-45mm and are the same price as the Power coil option. Your best bet is to call someone like Demon Tweeks and ask what different options are avaliable or you could try looking at www.needforspeed.co.uk
Mike