The springs length should be matched to the shock, it's rate, should be matched to the bike.

Yeah fair enough, well I'll just get the 10mm bush/adapter collar made up then and see how it runs, if it's to have more initial preload, I'll just add some washers to fix it up.

I'm not to worried about the valving, I don't think I'll have too many problems with the riding I'm doing, and it will be 100% better than my current shock, I'm sure.