Hi Moose,
Try calling these folks:

http://www.metricscrew-toolco.com/

I have dealt with them for years and they have found some odd stuff for me. However, I can tell you that 7mm h/w is very rare. I would just about bet your bolt was a custom job for Suntour. You may find that drilling out to accomodate 8mm or using washers with 6mm h/w is a much more expedient solution. Metric Screw&Tool will almost certainly tell you if that part is not available anywhere, short of having it made. They do stock 7mm nuts, washers, and taps, and a precious few 7mm bolts - but none that are that long. Call them. Good luck.