Personally, I would use the 100, for this reason. The wheel will start about halfway back ion the dropouts. Over a LONG time the chain will wear and you'll move back a little further but not much. I like the handling with a little length to the wheelbase.
If you start with the 98, even though its the prescribed length, the wheel will be pushed all the way to the front of the dropouts. If it were the old chains, you could expect the wear to cause you to use the whole dropout length. after all Honda put alignment marks down that whole length.
But with the new chain you'll never get back to the halfway point. So you've committed to a short wheelbase for the next 5 to 10,000 miles.
Personal preference.