Where do you get Valve shims ?

[ajcommercial]

Hiya All... Just a few questions..

  I am going to check the valve gaps and want to be prepared..
 I recon the gaps will be well out as I have had the van 65k miles and never checked them..

  I have Googled ( as all good men do ) and seen a method using a sheet of glass and fine wet and dry to thin the shim down. Anyone tried this ?
 Another method is to use a wet stone. Anyone tried this ?
 There was also a method using a but and bolt and a bench grinder.... this method just made me giggle...

Where did you get your shims from ? Are they all 13mm in DW8 and TUV ?


Thanks in Advance..