I changed my brake and clutch faster cylinders this summer, following advice on this site I went for the Discaciati master cylinders which come with the brake switch.
These were delivered in one week, if you have a VAT number you can get them tax free!!!
Visit
www.redracingparts.com The results are incredible, if you go for the clutch MS i would recommend the modified slave cylinder aswell.
And finally buy yourself one extra brake/clutch lever just in case as i doubt you will find one in the UK