I have always been too paranoid to mess with needles also. But if you use that DIY you don't have to, all you're doing is switching the circuit board from your 98-00 to the 01-02.
Once I read that fixing needle accuracy (for the speedometer) is something like you drive with a GPS telling your MPH, and fix the needle with your hand, while driving at 60 mph on a freeway w/ cruise control.
(A little dangerous, but this can also fix some inaccuracies by different tire diameters.)
needles aren't hard. did make a 91 civic 'si' out of a dx. You have to re-fab the cluster, dx's have temp & fuel in place of the tach. You do loose those, but i had other gauges. You only need a gauge, not cluster. I think I used an 89 (88-89 was different cluster than 90-91).
As long as they say '0' when you start, and '0' when you finish...you'll be fine.