try this to start with
http://atomic-carbon.gforceimages.ne...15-06-2007.jpg
I know its from a wet grass-track setup - but it was super-grippy because it was so wet
I would proberbly go with blue front springs and pink rear springs.
outside hole shock position on the front wishbone if its got too much steering.
depends how much grip the carpet generates, some carpet does not give that much grip.