Robinsons for Suzuki shims will take around two days to arrive if they have them in stock...
http://www.robinsonsfoundry.co.uk/sh...vehicle_id=114
Wemoto also do shims.
The blueproof link above misses some important info regarding positioning the crank. Most problems seem to arise from not studying the process of which there are two. Checking clearance and adjusting clearance. The crank is not positioned the same way for both processes leading to problems reinstalling camshafts durng the valve adjustment process.
I'd start by reading up first on how to check clearances and leave adjustment until later.