Untill Brent gets some risers together, here is a link to the Custom Chrome catalog. They have risers ranging from around $70 up to astronomical. Look in the index for what you want, then click on the page number to hotlink ot the page.
Don't forget that this stuff is mostly for HD, so you will probably have to use inchic instead of metric bolts.

http://www.customchrome.com/catalogs/ccp/t.html

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python